Art critic and forgery expert George Steele (Pat O'Brien) is apprehended by the police as he desperately tries to break into the Manhattan Museum in the opening scene of Crack-Up, a noir mystery directed by Irving Reis. Steele does not understand his own bizarre actions, but explains that he was in a train wreck and had to get back to the museum. Questioned by Lt. Cochrane (Wallace Ford), who tells him there have been no train wrecks in months, Steele relates, in flashback, the events leading up to the incident. Earlier in the day the head of the museum had suspended him for alienating wealthy patrons by criticizing "art snobs" in a lecture. He then received a phone call informing him that his mother was sick, and caught the train to the hospital, but never got there. Though suspicious of Steele, Cochrane is persuaded by the shadowy Mr. Traybin (Herbert Marshall) to release him so he can follow Steele. The next day Steele retraces his steps and discovers that someone had set him up to be discredited, though he knows neither who nor why. Following the murder of a friend who was trying to help him, he discovers that forgeries of some very famous paintings are at the heart of the matter, but getting to the culprit is a more difficult task.