Between your cases in Sherlock Holmes Chapter One, you will find dozens of delightful side-cases to keep you sharp and help you earn a couple of bucks on the side, too. You can find the side case, A Mad Rogue, upon passing the Fortress of the Holy Spirit Ruins at the intersection of Bazaar Rd and Medrese St in eastern Old City.
To begin, pin the clue Our Secret and use Concentration Mode to investigate the ruins near Jon.
Stay in Concentration Mode and turn around to find a trail of Sherlock's recalled memories. Keep following this trail and investigating each spot that materializes—it will eventually lead you to a burial spot. Interact with the rocks here and you will find a human skull.
Examine the skull, and you will hear a short exchange of dialogue describing the shocking potential identity of the remains. Afterward, you will automatically complete this side case and earn some interesting information to investigate in your casebook.
For more guides and secrets in Sherlock Holmes Chapter One, check out All Bandit Lair Locations in Sherlock Holmes Chapter One, and stay tuned to Pro Game Guides for continued coverage on all of your favorite games!