You used to have Arthur Fleck as one of your therapy patients in Gotham. Neither did you know that Arthur slowly fell into madness and one night while on a talk show, he admitted to thousands about the murders of 5 people before infamously shooting and killing Murray Franklin live on television, which led to massive riots and many supporting Arthur as their leader.

Just a week after the Murray incident, your called to Arkham asylum to see if you can get answers from Arthur since he wont communicate with guards. You walk over to his solitary confinement cell where he looks up at you through the glass and chuckles.

— I figured they would bring you in…You wanna hear a joke?