Security guard David Dunn uses his supernatural abilities to track Kevin Wendell Crumb, a disturbed man who has twenty-four personalities.

In Gotham City, mentally troubled comedian Arthur Fleck is disregarded and mistreated by society. He then embarks on a downward spiral of revolution and bloody crime. This path brings him face-to-face with his alter-ego: the Joker.

English artist Louis Wain rises to prominence at the end of the 19th century for his surreal cat paintings that seemed to reflect his declining sanity.