In Dying Light 2 Stay Human, The Deserter side quest becomes available at the Duties board in the PK Floating Fortress after you complete the Broadcast story quest. Meyer tells you that she suspects a Peacekeeper named Bart of stealing a map and deserting the Peacekeepers. Your first objective is to search his bunk.
As your investigation continues, you’ll learn that there’s much more to this situation than Meyer realizes, and the evidence that Bart is not only innocent, but that he’s actually a really awesome guy, keeps mounting up. Eventually you’ll find Bart and Andy in a building near the Metro lines west of Juniper Windmill. They admit to stealing the map and deserting, but they claim that the Peacekeepers are the bad guys here, and offer you a deal. You can agree to help, or decline to help.
Unless you’re really loyal to the Peacekeepers, you should agree to help Bart and Andy because they’ll give you the treasure map that unlocks the Treasure Hunt side quest. If you don’t agree to help them, then you’ll be locked out of the Treasure Hunt side quest, and will never find out what the treasure map leads to.
