Struggling with his dual identity, failed comedian Arthur Fleck meets the love of his life, Harley Quinn, while incarcerated at Arkham State Hospital.

In 1981 Gotham City, a struggling, mentally ill comic battles to be seen. His life takes a dark, gut-wrenching turn after he lashes back at attackers.

When he is betrayed by a trusted friend, Mathayus must marshal all his strength and cunning to outwit a formidable opponent who will stop at nothing to unlock a supreme ancient power.