Mystery Detective Adventure Walkthrough – Case 3

Mystery Detective Adventure is a murder-mystery indie title. In order to complete the entire game, you will need to solve all three cases, collect all the collectibles, then complete the secret case. We have covered the first two cases, and so it's time to head into the third case in our final walkthrough. For the other cases, check out:

• Mystery Detective Adventure Walkthrough Case 1
• Mystery Detective Adventure Walkthrough Case 2

Mystery Detective Adventure Walkthrough - Case 3: Mine Accident

In the first two cases, Detective John Woodbray has had to take on a murder that was covered up as a suicide and what seemed like a giant demon dog attacking a small town. With those two cases solved, it's time to take on an apparent murder in a mine. With his handy portable laboratory, Woodbray is ready for to take on the mine.

Entrance of the Mine

You start in the entrance, and you meet up with the head of the mine, Margaret. She gives you a Pass to the mine. On her desk, you can pick up the Newspaper, and under the newspaper is a Clip to take. Leave her office, and you will be back in the Entrance location. There are several things to look at and ways you can leave this location.

• Starting on the left of the image above, the first arrow leads into Margaret's Office.
• A little to the right of the office door is a Red Lock Box. Use the Clip from Margaret's office to open it up and take out the Hammer and the Detail piece.
• The sliding glass Window to the right of the electrical box is locked with two metal pieces you don't have yet.
• Right above Woobray's vehicle is the Entrance to the Mine itself.
• There are two doors you can enter the building in the middle; the one on the left goes to the Workshop.
• The door on the right side of the building in the middle is locked, and you can't get in just yet.
• The gate heads into Town.
• There is a Water Pump all the way to to the right. Interact with it, and pick up the Hose item that is attached to it.
• On the roof of the building in the middle is a Morphing Object.

Mine

Now you can go into the Mine itself. Walk over to the red elevator door and use the Pass that Margaret gave you. This will bring you underground. There will be an old man there that you will automatically interact with; he will give you a Key.

• There is a Morphing Object right next to the old man on the rusty box.
• You can also interact with the Rusty Box itself, but you can't open it yet.
• There is a locked gate that heads to the left further into the mine.
• You can head to the Right further into the mine once you have the minecart working.
• There is a Switch on the rails that allows you to pick which direction you can go with the minecart.
• If you interact with the Minecart, you can pick up both a Dirty Part and a Detail with a Fork.

The Boiler Room

With the key to the Boiler Room in hand, go back up out of the Mines to the Entrance. Click on the right-most door on the screen, which will zoom you in on a set of locked double doors. Use the Key the old man in the mine gave you to unlock it, and head inside. You will need to find all the objects outlined at the bottom of the screen to finish this section.

• Pick up the Valve (1) off of the floor over the grate.
• Click on the boiler in the back left of the room. Pick up the Rope (2) and the Bucket (3).
• Click on the mechanism on the left front of the room; there is a Shovel (4) behind it that you can pick up.
• While still looking at the mechanism, put the Valve on the it (5).
• Using the Shovel, add some more coal to the Boiler (6).
• Take the Bucket and fill it with water from the Water Barrel (7). Pick up the Token from inside the barrel.
• Put the Water from the Bucket into the boiler (8).
• Click on the mechanism, turn the Valve, then pick up the second Token (9) from under the hammer.
• Use the two Tokens to open the Shelves (10) in the back right of the room. Pick up the Wrench and the Chisel from inside it.
• Use the Chisel on the wall (11) to get the Hook.
• Click on the grate in the middle of the floor again (1). Use the Wrench to open it up, then used the Rope and Hook to get the Jerry Can out of it.

Workshop

Go into the Workshop; the door to it is a little to the left of the Boiler Room door. Once inside, you will be able to get gas for the minecart, find a couple of collectibles, and look at some other objects. Here's everything you can interact with here:

• The Morphing Object is located on the bottom left.
• There is a puzzle where the blue panel is, but you can't do anything with this just yet.
• The Gas Can in the center of the room can fill up the Jerry Can. First, open the cap on the gas can, then place the Jerry can next to it. Use the Hose from the Entrance to the Mine to fill the can for the minecart.
• The Workbench has a Lightbulb on it you can pick up. Also on the workbench is a Detail Piece in a vice. Use the Hammer on it to get it out.
• Under the Workbench is a Hard Hat Collectible.
• The is also a Drill, but you can't interact with it yet.

Entrance to the Mines

Once you have finished all the above steps in the Workshop, back out to the Entrance to the Mines location. Use the two Detail Pieces with the fork and spoon on them to open the little sliding glass door on the supervisor's office by the entrance to the mines. There will be an Anchor Collectible inside. If you take a closer look at the box on the table in the room, it will zoom in enough for you to see the Detail Piece with the arrows on it. Pick that up, then interact with the box. This will start the Fruit and Vegetable Puzzle Box.

The Fruit and Vegetable puzzle box solution

You have to line all the fruits and veggies up on the top of this box to solve it and open it up. I have tried it several ways, but this seems to be the only layout that works that I have found so far. This puzzle's answer should be the same for everyone. Put all the foods in the right spots to open up the box and get the Knife.

The Place of Death

Once you have the Knife and the Hammer, you can make your way to the Place of Death. Go back into the mines and interact with the minecart. Pour the Jerry Can filled with gas into the minecart, then start the engine with the pull cord. Use the Hammer to move the wedge holding the minecart in place out of the way. Make sure the flag in the middle of the tracks is facing to the right, then exit out of the screen to the right mine.

This location is the Place of Death. The first thing you have to do when you come in is to replace the Light Bulb in the flood light to the right of the screen. If you picked up the Bulb from the Workshop, you should be able to get it working again. This will light up the crime scene.

• The boards on the left side of the screen are interactable, but you can't interact with this just yet.
• Above the boards is a Morphing Object.
• You can interact with the Crane, but you can't do anything here yet.
• Next to the crane is the Body. Click on the body to zoom in, then use the Knife to cut it off of the body. Inside the bag will be a Key.
• A little to the right scoop of the excavator on the wall is a Bullet (Death of Henry: Evidence 1/4).
• On the floor on the right side of the screen is an Anchor Collectible.

Now that you have the Key from the body's bag, you can unlock the Rusty Box in the mouth of the Mines by the old man. Inside this box is a Hard Hat Collectible and a Pickaxe. After you pick these two up, head back to the Place of Death.

Use the Pickaxe on the boards on the left side of the screen at the Place of Death; this will pull the boards off of the wall, revealing the water pump Lever. In the Entrance to the Mine, use the Lever on the water pump where you got the Hose at the beginning of the game. Use the water pump to clean off the Dirty Detail with the arrows on it. Now you should have all three Details for the Arrow Detail Puzzle, which is located inside the Workshop.

Arrow Detail Puzzle in the Workshop solution

Take all the Details into the Workshop and put them into the blue panel in the middle of the screen. This will open up a puzzle. The point of the puzzle is to switch the red plus and the blue minus. You also get an achievement if you complete it in less than 80 seconds, so here is a video of how to do it as fast as possible. After you complete it, the compartment behind the puzzle will open up, giving you a Screwdriver and a set of Drills. This puzzle is not random, but is the same for everyone.

Fingerprinting the Dead

Go to the Entrance of the Mine, and click on Woodbray's vehicle to get inside. Pick up the Fingerprinting Kit, the Tweezers, and the Evidence Envelope from inside. Return to the Place of Death, and use the Fingerprinting Kit on the body to get the Fingerprints, then pick up the Gun next to the body with the Evidence Envelope.

Return to Woodbray's portable lab car and use the Fingerprints and the Gun to start a little puzzle. You will need to match the fingerprints on the paper to the ones on the gun. Match up each fingerprint shape to the identical one on the gun. Once complete, you'll get the Gun (Death of Henry: Evidence 2/4)

Crossroads

The Crossroads can be accessed from the Entrance to the Mines location where you vehicle is. Head north through the gate a little to the right of the Boiler Room door. On the other side, you will see a little intersection where you can get to the Marina and into town proper.

• There is a puzzle on the gate on the far right of this screen, but you can't interact with it yet.
• On the stairs, there is an Anchor Collectible.
• Under the tree, the arrow points the way to the Marina; you don't need to head there yet.
• There is a door closed by a rope; cut the rope with your Knife to get inside, and pick up the Blue Chip and the Ladder.
• The fish sculpture has a Hacksaw Blade for a nose. Use the Screwdriver to get it.
• To the right of the fish sculpture is the entrance to town. You don't need to go there yet.
• The sign on the right-most building is a Morphing Object.
• The giant vase on the right has the Yellow Chip in it, but you can't get it yet.
• There is a Barrel filled with Oil on the bottom right that you will need later on.

Go back to the Place of Death and use the Ladder on the excavator. This will allow you to look more closely at the top of the crane and see more clues. If you open the metal door at the top, you'll see a Handprint (Death of Henry: Evidence 3/4) and that the Rope was Cut (Death of Henry: Evidence 4/4).

Go back to the Entrance of the Mine and speak with the Miners that will be there. They will tell you to look for a man named Jacob, and that he can most likely be found in his home. To get there, go north to the Crossroads, then continue up to the right to get to the Entrance of the Miner's House.

The Entrance of the Miner's House

Going through town will get you to Jacob's home; it seems to be empty, and the front door is locked. You will need to go around back to try to break in.

• The Front Door is locked.
• There is a Morphing Object in the form of a leaf hanging in the middle on the end of the long branch.
• You can click just underneath the morphing object to go to the backyard.
• There is a Bird's Nest with a Chip inside it, but you can't reach it yet.
• There is a small outbuilding to the right of the house; it is locked with two detail pieces.

Click to go around back of the house and pick up the Fleur-De-Lis next to the dog house, then interact with the back door. If you look into the Lock of the back door, you will see that the Key is in the lock. Put the Newspaper underneath the door, then use the Screwdriver to push the Key out of the lock; it will fall to the newspaper, and then you can pull out the newspaper and pick up the Key off of it to unlock the back door.

Jacob is inside the house dead, hanging from the neck. You will have a variety of things to interact with here in order to solve this staged suicide. Here are all the objects and places you can interact with in Jacob's home.

• On the front door is Jacob's Mailbox. Inside, there is a Letter (Death of Jacob: Evidence 1/5) and the green Chip.
• To the left of the body is a dresser with a picture on top. Use the Screwdriver on the picture to get a Leaf out of the frame.
• Next is the body; you will need to cut Jacob down before you can do anything with him.
• To the right of the body is a bag that is holding him up. Interact with the bag to zoom in, then click on the Handprint (Death of Jacob: Evidence 2/5). There is also an Anchor Collectible next to the bag on the shelf to the left. Cut the rope holding the body from the bag with the Knife.
• Now that the body is down, you can interact with the Rope around Jacob's neck (Death of Jacob: Evidence 3/5).
• Underneath the wood chair in front of the bed is a Bottle of Sleeping Pills (Death of Jacob: Evidence 4/5).
• On the floor on the right side of the room is a red cloth. There is something stuck in between the cracks of the floorboards, and you can grab this Piece of Paper with the Tweezers.
• There is a Morphing Object on the wall on the far right side that looks like a stick figure.
• You can interact with the desk drawer, but you can't open it yet. While zoomed in on the desk, though, you can collect the Wheel and the Matches.
• There is a puzzle locked cabinet just above the desk. Use the Paper you got from the floor underneath the puzzle to know how to open up the cabinet.

Jacob's house cabinet puzzle solution

In order to open the cabinet up, you'll need to figure out the cabinet puzzle and make it match the picture you found in the floor; this picture is not random and will be the same for everyone. The best way to start is to rotate the blue bricks until the bricks are in the right place in the bottom right corner. Then move the red bricks in a circle until the very center piece is a yellow sun square. Move the final red piece into the square and swing it around to fill in that corner. Now that you have both the red and blue corners done. Spin the purple around, pulling the green away and down, then spin them until they are both filled in. Once you have completed the cabinet puzzle, you'll get a Fleur-De-Lis piece. Here is a video to help you through the process of finishing this puzzle.

Shed puzzle outside the Minor's house

You should have two Fleur-De-Lis pieces now, so you can open the shed next to the Minor's home. Go outside and interact with the door to the shed. Put the two Fleur-De-Lis pieces into the shaped slots, and you will be given a puzzle. This one is pretty easy; you just need to line up the holes in the metal piece over the shapes of the items in the door. Make sure none of them overlap, and the door will open.

In the shed, take the Hook from in front of the dresser inside. Use the Hook to prop the dresser up, and then slide the Wheel from the desk inside underneath it. This will let you roll it out of the way. There will be a Leaf inside the hatch under the drawers as well as a Hacksaw Frame. Above the dresser on a shelf is another Hard Hat Collectible. Now that you have the Hook, you can use it to knock the Chip out of the bird's nest outside the Minor's house and pick the second-to-last Chip out of the vase in the Crossroads.

Combine the Hacksaw Frame and the Hacksaw Blade to get a Hacksaw. Return to the Minor's house and use the two Leaf pieces you have to open the Drawer of the Desk. Inside will the last Chip and a newspaper clipping about the murder five years ago (Death of Jacob: Evidence 5/5).

Octopus Gate Puzzle in the Crossroads

Since you have all five Chips, you can enter the Octopus Gate in the Crossroads. So go to the gate, click on the gate and use the Chips on it. It will put all but one chip in place; you will then get the Blue Chip back and it has been remained as the Wrong Chip. Since it doesn't fit, take it back to the Workshop. Use the Drill Bits on the Drill, then put the Wrong Chip down on it. Use the crank at the top of the drill to use it. This will give you the chip back with the proper holes in it.

This will start the Octopus Gate puzzle. In order to complete this one, you just have to match the symbols on the chips to the ones engraved underneath each of the chips. Here is a video on how to complete it.

The Bridge

Walk through the gate now that is it open, and head into the next section. This is the Bridge, and there is yet another body for Woodbray to look at. There are only a couple of things to look at for now, at least until you fix the bridge itself.

• On the left of the entrance to the bridge itself, there is a Thorny Bush with something inside it. Use the Knife on the bush and get the Bag.
• On the right side of the bridge's entrance, there is a gearbox. On it, you can find a Handprint (Death of Michael: Evidence 1/4). Also remove the Broken Gear from this box.
• If you try to climb down by click on the area right of the stump, Woodbray will insist on finding a safer way down.
• There is Morphing Object on the other side of the bridge; it's a tree that changes shape.

The Marina

In order to get down to the body, you'll need to head to the Marina, which can only be accessed through the Crossroads. Take the passage under the tree, then walk to north in the middle of the screen and not toward the house. You will be in the Marina, and you can speak to the Captain.

• There is an Anchor Collectible to the left of the Captain on the boat.
• You need to speak to the Captain on the boat to get the Rope Ladder. She will ask for a bottle of rum. To get the Rum, go into the door on the right of the screen and give the bartender the Bag you found by the Bridge. She will give you Rum to give to the Captain in exchange for the Rope Ladder.
• There is a Morphing Object in the background on the pier. Look for a small box a little above and to the right of the Captain's boat.

Head back to the Bridge location and use the Captain's Rope Ladder to make your way down to the next murder scene. You will need to zoom in on the stump, then use the ladder on the roots.

The Third Murder Scene at the Bridge

Climb down to the murder scene. There will be several items to interact with here, including a collectible and the body itself. First, you want to pick up the Hard Hat Collectible from the left of the body. Then interact with the body itself, and take the Key out of his pocket. Open the carriage door; there will be a Stone on the seat inside. Last, open the box on the right side of the screen with the Hacksaw, and get the Handle and the Valve.

Now, you will need to head back to the Fork where the path to the Marina is. There is a locked house on the right, and another locked house in the background of the left part of the screen. The Foreman's house is the one on the left. With the Key from the body, you can get inside. But first, there are a couple of things you'll want to interact with outside the house, in the Fork location.

• The Foreman's home is the distant house on the left.
• There is a Morphing Object on the fence to the left of the bicycle. It looks like an oar.
• Interact with the bike; there is a locked pouch on it. You can't interact with the pouch yet, but you can take one of the bike's Spokes from the wheel.
• There is an Anchor Collectible on the left side of the house on the right.
• The right house's door is locked; you cannot get in yet.
• This press can't be interacted with yet.

The Foreman's House in the Fork

Use the Foreman's Key on the Foreman's house in the distance, and head inside. There will be a ton to do in here, so make sure you are looking through everything carefully. Let's start on the left side of this location, and we'll work from the yellow circles on the left of this image to the right.

• The Clock on the wall. It's missing its face.
• Interact with the Strange Painted Symbols on the wall (Death of Michael: Evidence 2/4).
• The pile of pillows has a Stone underneath it.
• You can look out the window, but there's not much to see.
• On the ceiling is an Attic Door; you need to find a way to pull it down.
• On the table is a box and a book. On the front cover of the book is an Anchor Collectible.
• On the wall is a strange lever that needs a handle of some sort.
• Next to the mirror, taped to the wall, is a newspaper clipping. If you click on the mirror, it will show a hidden safe in the wall.
• You can zoom in on the stove; use the Handle you got from the box at the car crash site and open it up. There will be a Lever inside. Use this Lever on the strange lever on the wall to open up the Door to the Attic.
• Underneath the stove, under the table, there is a Morphing Object.
• You can interact with the window. Use the Knife on the window, then take the Stone out of the place between the window panes.

Now that you have used the Lever to get into the attic, climb up the stairs. The room will be way too dark to see much, but you will be able to pick up an Oiler and the Face of the Clock from the one chair that is in sunlight. Take the Clock Face back into the main room of the house, then put it in the empty clock. This will open up a secret compartment and give you Part of a Code and the last of the four Stones. Put the four Stones into the box on the table in the middle of the room, and you will get a puzzle to figure out.

The Stone puzzle in the Foreman's House

The Stone puzzle is a strange a difficult puzzle if you don't get it. In order to complete all the stages of the puzzle, you need to figure out what you would need to create each of the items on either side of the top of the puzzle. Here are the combinations:

The Foreman's Safe Puzzle

Once the box is open, you will get the other half of the Code needed to unlock the Foreman's Safe. The safe is located behind the Mirror in the middle of the room. This one is a little odd, because the solution will be different for everyone. I can share my numbers though, so you can see how it was done.

The first is the easiest; you take the number that the Gear + Gear + Gear is equal to and divide it by 3; in my case it makes the Gear = 5. Next, you need to figure out what numbers will equal up to 26; in my case, I knew that the Nut had to be the higher number since Nut + Nut + Bolt is 26 while one Bolt, one Nut and one Gear only equals 19. If you add 12 + 12 + 2, you get 26, and you also get 19 when you add up 2 + 12 +5, so I knew that the Nut was 12 and the Bolt was 2. So this follows that my first answer is 12 + (2 x 5) = 22. The second solution is 12 x 5 - 2 = 58. Third is 8 + 5 + 2 = 15. So the numbers for mine are 22, 58, then 15.

The gears in the attic

Inside the safe will be a letter about the ghost (Death of Michael: Evidence 3/4). Now that you have this evidence, you can return to the Attic where you will be able to open the window. There will be 15 total gears to find. There are nine gears located around the room; the 10th one is underneath a board that is nailed down and you need to use the crowbar on the left side of the screen to pry it up. The others are in the starred places: the trunk and the window. There are three gears in the trunk; one is on top and the other two are under piles of clothes. In the window, there is one etched into the glass, and the second, you need to pull up the curtain and it will fall out.

The Entrance to the Lighthouse

Now that you have collected all the Gears, take them to the Bridge location and use them to fix the bridge's mechanism. This will allow you to go to the Entrance to the Lighthouse. This location will have several things to interact with.

• On the left of the house, there is a bench with something stuck in it. Use the Tweezers to get the Dolphin out of the crevice.
• Next to the bench is an Anchor Collectible leaning against the house.
• Under the bench on the ground, there is a grate that is rusted shut. Click on it and pick up the Key from the bottom left of the screen.
• The door to the house is locked, but you can find the Key for it on the rusted grate.
• There is an old boat in the middle of the screen; use the Knife on it to get a Token.
• The entrance to the lighthouse itself is locked with a metal gate.
• There is a Morphing Object on the bottom right of the screen; it goes from being a little shell to a sea star.
• Use the Key you found on the rusty grate to open the house and go inside.

The House by the Lighthouse

The house will be pretty dark when you first enter, so you need to use the Matches from Jacob's House on the lantern. This will give you a good look at the room and everything you can interact with.

• In the upper right corner, there is a hanging boat with a Morphing Object on it. It changes from an A to an X.
• The stove can be lit with a Match.
• There is a Hard Hat Collectible on the chair by the stove.
• Above the chair is a locked panel that requires two Dolphin shapes to unlock. We've only found one of these so far, so you can't interact with this just yet.
• Under the bed is a lockbox with a puzzle on the front of it.
• There is a large red door on the left side; use the Valve from the car accident scene by the Bridge to open it.

The House by the Lighthouse Puzzle

The first thing you want to do after collecting the morphing object and the hard hat collectible is to open up the lockbox in the center of the room under the bed. In order to complete the puzzle, you just need to put the symbols that match the background in the right place to line up. So the palm tree, for example, should end up on the left middle slot to match up with the trees in the background. Here's how to do it:

After this puzzle is complete, you will get a Tap, a box of Nails, and a Token from inside the lockbox. Use the Valve from the Bridge to open the Red Door on the right side of the House by the Lighthouse. This will give you another hidden object puzzle.

Hidden object puzzle in the House by the Lighthouse

Once you have opened the red door with the Valve, you will find a hidden object puzzle on the other side. There are 10 objects to find.

• First, pick up the Ice Skate Blade from the box in the center of the room (1).
• Get the Glove from the left (2).
• Use the Glove on the box filled with broken glass (3) to get the Handle.
• Use the Ice Skate Blade on the wall (4) to get the Glass Cutter out.
• Take the Glass Cutter, and use it on the diver's helmet to get the Coin (5).
• Use the Handle on the cabinet in the upper right (6). Take the second Coin and the Lighter.
• Interact with the prison-like door (7) to take the Key.
• Use the Key on the box in the upper left (8). Inside will be Gunpowder and a String.
• Go back to the prison-like door (7). Use the Gunpowder on the lock first, then the String, then the Lighter. This will blow up the lock.
• Use the two Coins on the locked box inside (9). Once the box is opened, there will be a Key inside to take.

Next, you want to take the Oiler you got from the Attic of the Foreman's House, the Tap you got from the House by the Lighthouse, and take it to the Crossroads. Use the Tap on the barrel of oil in the bottom left corner of the screen, then use the Hammer to drive the Tap into the barrel. Click the Oiler on the barrel to fill it up with oil. Bring the Oiler with Oil back to the House by the Lighthouse, and use it to oil the grate on the ground near the house. You will then be able to open it and use the Hook on the box to pull the box up. Open the box; inside will be a Token and a Token Stuck in a Melted Candle. Take the Token Stuck in a Melted Candle into the House by the Lighthouse, and use the lit stove to melt the wax, then retrieve the Token.

The Lighthouse

Take the Key you got from the hidden object puzzle inside the House by the Lighthouse, and use it on the locked gate in front of the Lighthouse. Zoom in on the door the Lighthouse, and you will see that you need five Tokens to get inside. You currently have four. Thankfully, there is a hidden Dolphin piece that you can use to open the Dolphin Panel inside the House by the Lighthouse.

Use the two Dolphins to open the panel, and there will be a Thank-You Card (Engineer and His Grandchildren: Evidence 1/6) and the final Token to get into the Lighthouse. Use them on the Lighthouse Door to start the Lighthouse Door Puzzle.

The Lighthouse Door Puzzle

You need to get the proper number of boats next to each of the tokens to open the Lighthouse door. So if the token has a number 1 on it, it can only have one boat next to it, and so one. It can be done in just a couple of moves, as shown in the video below.

Once you are inside the Lighthouse, climb the stairs, then interact with the symbols on the lights. This will give you the symbols clue (Death of Michael: Evidence 4/4) for the Foreman's clues. Return to the Entrance to the Mines, and go into Margaret's Office. She'll give you a Key to the locked gate in the mines.

The Mine and the Grave

Open up the gate in the Mines with the Key Margaret gave you, then pull the lever to change the direction of the tracks to go to the left inside. Use the minecart, and you will find yourself in a tunnel that branches three ways.

• First go Left, then Left, then Straight. Grab the Shovel in this location.
• Hit the Back button twice, then use the Shovel to clear the debris from the right tracks. Change the tracks' direction, and use this to head into the Right tunnel.
• Pick up the Jack.
• Hit Back button twice.
• When you are back at the original three-tunnel hub, head to the Right, then Right again.
• Use the Jack on the sagging part of the minecart tracks.
• Now that the tracks are fixed, go Right again. Pick up the Key.
• After getting the Key, go Back once, then switch the direction of the tracks to go Left.
• Use Key on the terminal to open up the three locked doors.
• Head to the Left tunnel, and pick up the Rope.
• Go Back one into the three-tunnel location, then pick the Center tunnel.
• Use the Rope to get down to the Mine Grave.
• Interact with the grave, and you will notice a box that has five slots in it. You will need five Pickaxes to open it up.
• They are located where the Stars are in the map of the Mine Maze above.
  • One can be found on the same screen as you found the Jack.
  • If you go back to the entrance, then take the middle tunnel, there is another pickaxe there.
  • Go to the screen where you used the shovel, then head left to find the third pickaxe.
  • The fourth will be where you found the key.
  • The fifth is right above the grave, stuck in the wall.

The note inside the box by the grave is a suicide note (Engineer and His Grandchildren: Evidence 2/6). After you have completed this section, go to the Workshop, talk to the old man, then go to the Marina bar, and talk to the barkeep. Look through the window in the bar, and you'll see a bloody weapon. Head back out the Marina proper, and walk around the other side of the bar. There will be the Bloodied Club (Death of Robert: Evidence 1/2). Use the Wood Boards laying by the club along with the Nails from the House by the Lighthouse and the Hammer to make a Bridge. Pick it up and take it with you.

Use the Bridge over the Marina to get to the other side. Interact with Robert's Body with the Hook, and then use the Knife on the netting around the body. There will be a Handprint on the back of the body (Death of Robert: Evidence 2/2), proving it is the same serial killer who killed the others. Go back to the Fork, and use the Bicycle Spoke to make a lockpick to get into the Engineer's House.

How to unlock the door to the Engineer's House

There is a quick mini-puzzle to get into the Engineer's House with the lockpick. You need to push up the numbers in the right order, which you have to figure out by trial and error. The order for me was: 3-4-2-5-6-1-7-8, as shown in the video below.

The Engineer's House

Now that you have gotten inside the Engineer's House, you are very close to the end of the game; you just have a couple more things to do before you can clean up this serial killer and arrest the suspects. There are loads of things to look at inside the entrance of the house as well as the bedroom.

• On the right side of the screen, there is an icebox being held up by books. Open the bottom compartment and use the Knife to carve the Detail out of the ice.
• Click on the blue door in the back of the room, and click on the Handprint (Engineer and His Grandchildren: Evidence 3/6).
• Underneath the table is a Hard Hat Collectible.
• There is a photo on the dresser in the back. Click on the Photo (Engineer and His Grandchildren: Evidence 4/6), then pick up the Bent Detail from behind the frame.
• On the chair furthest to the left, there is a Morphing Object that looks like a box.
• You can interact with the books on the bookshelf.
• You can interact with the puzzle on the left side of the bookshelf.
• Click on the couch, use the Knife on it, then take the Rotating Dial.

• There is a trunk on the far right of the screen; use the Rotating Dial on it to get ready to fill in the numbers.
• Under the bed is a Hard Hat Collectible.
• There is a Bag on the top of the bed; use the Knife to cut it open and take the Key out.
• Next to the bed to the left is a side table with some paper on it. Interact with the Newspaper Clipping (Engineer and His Grandchildren: Evidence 5/6), and take the Bookmark as well. Click on the mechanism keeping the bottom part of the side table closed, and use the Bookmark on it. The doodles of the symbols on the lock will match up with the numbers on the bookmark. For me, the solution was 3-8-7-1-2, but it may be different for you. Opening this cabinet will get you a Winding Key.
• The patch on the desk on the left is a Morphing Object.
• Interact with the boat toy on the desk. Use the wheel laying on the desk on the boat, then use the nut laying on the desk to lock the wheel into place. Use the Winding Key to wind up the toy, and you will get another Detail.

The Bookshelf puzzle in the Engineer's House

Go back to the Fork, and use the Key from the bag in the bedroom of the Engineer's House to open the locked bag on the bicycle. Inside will be the last of the four Details and the Book needed to complete the Bookshelf Puzzle inside the Front Room of the Engineer's House. Solve it by putting the Roman numerals in order, lowest to highest. Inside will be a little hidden nook with Alcohol inside.

Use the Alcohol on the dirty floor by the Trunk in the Bedroom of the Engineer's House, and this will give you the solution to unlocking the Trunk. It may be different for you, but my numbers were 82-71-63. Recreate these numbers on the two Rotating Dials on the trunk; it doesn't matter which way you spin the two dials.

Take the Valve out of the trunk. Return to the Fork. Use the Valve on the Press by the Engineer's House, then put the Bent Detail into it. Click on the machine to flatten the Bent Detail, and it will turn into the fourth Detail you need to solve the Detail Number puzzle on the Bookshelf in the Front Room of the Engineer's House.

Detail puzzle solution (Front Room of Engineer's House)

The basic premise of this puzzle is that you have to add or multiply all the numbers in the center to get all the numbers on the outside. Below is a video of my solution to help you out, and below that the order I had to do them in.

(I found the easiest way to solve this one was to start with the biggest numbers in the center to make the biggest numbers on the outside first, and work my way to the smallest to give myself some leeway inside the puzzle's mechanism. Solving the puzzle will give you the Key to the blue door in the Engineer's House.)

• 15 = 9 + 6
• 16 = 4 x 4
• 4 = 3 + 1
• 11 = 9 + 2
• 9 = 8 + 1
• 13 = 8 + 5
• 10 = 7 + 3
• 14 = 7 x 2
• 12 = 6 x 2
• 8 = 5 + 3

The Timed Puzzle in the Basement of the Engineer's House

Before unlocking the door to the basement: make sure you have collected all the Collectible objects, as there is no turning back from this point. Unlock the door to the basement, then watch the cutscene. This will begin a timed puzzle. You have Two Minutes to finish it before you have to start over.

• Grab the Pliers off of the floor by the blue cabinet.
• Interact with the workbench in the center of the room, and knock over the can of odds-and-ends. Move things around until you find the Part of the Key.
• Take the Broom from in front of the blue cabinet.
• Use the Broom to knock the Scissor Part from the top left corner of the screen.
• Use the whetstone on the workbench to the sharpen the Scissor Part.
• Click on the blue cabinets, and use the sharpened Scissor Part to cut the Arrow Piece tied to the pipe on the right. Then, use the Key Part and the Pliers to open the blue cabinet. Inside will be some Oil in a bucket.
• Use the Oil on the large shelves to the right of the screen to move them under the window.
• Click on the window and take the Magnet on a String from the windowsill.
• Interact with the grate opening that was underneath the shelves you just moved, and use the Magnet on a String to pick up the second Arrow Piece from inside the grate.
• Use the two Arrow Pieces to open up the upper cabinet.
• Take the Hacksaw out, and then use it to cut open the window.

This is the end of case 3 and the end of Mystery Detective Adventure. There are several mini-games and other things you can play in the main menu, but this is the final case.

• Mystery Detective Adventure Walkthrough Case 1
• Mystery Detective Adventure Walkthrough Case 2

All collectibles in Mystery Detective Adventure Case 3

Just like in the previous chapters, there are two different types of collectible objects and several morphing objects to get. This case has Hard Hat Collectibles as well as Anchor Collectibles. There are eight of each of those collectibles and 15 Morphing Objects.

All Hard Hat Collectibles in Case 3

All Anchor Collectibles in Case 3

All Morphing Objects in Case 3

For more full walkthroughs of indie games, check out Riven (2024) Walkthrough – 100% All achievements & endings on Pro Game Guides.