You are all Undercover Agents hired to investigate each other.
Some of you are law-abiding agents fighting for justice. Others are crooked operatives corrupting the law. You all meet at the same rendezvous point, but since everyone is undercover, no one is sure who is on their side.
To signal to one another, law-abiding agents always speak the truth and corrupted operatives lie. One bullet left to hurt the defector. A medical kit to heal your fellow operative.
So, truth or lie, who’s on your side?