Steele, unsure himself what happened, relates the bizarre events leading up to the present: After giving an enthusiastically received lecture on art, Steele had been reprimanded by Museum director Barton (Erskine Sanford) over his sensational style, and denied access to X-ray equipment to demonstrate a forgery detection method on a masterpiece that had recently been exhibited by the museum, Dürer's Adoration of the Kings.

Afterward, while having a drink with his girlfriend, magazine writer Terry Cordell (Claire Trevor), Steele had received an urgent telephone call informing him that his mother had been taken to a hospital.

Stevenson, the curator and Steele's friend, and Dr. Lowell (Ray Collins), a member of the museum's board of directors, vouch for his character.

Steele is released, but his contentious lectures are canceled by Barton at the direction of the museum board, and he is suspended from work because of his evident mental instability.

Steele follows Barton to a party given by a museum board member, where he learns that the shipment of the Dürer back to London has been unexpectedly advanced.

Traybin, an undercover Scotland Yard inspector, had all along been investigating the suspicious Gainsborough loss, and seeking to ensure the safe return of the Dürer.

He wrote, "Since Pat O'Brien's noggin suffers a blow which blacks out his memory as the story starts, there probably wouldn't be much sense taking the authors to task for the fantastic events which ensue ...

This explosive and promising action sets in motion a chain of circumstances which, no doubt, must have baffled the script writers, too, for they never do give it a logical explanation ... All of the aforementioned principals turn in competent performances, and the mystery is how they managed to get through the picture without becoming hopelessly confused.

Played at breakneck pace, Crack-Up might have succeeded in covering up its confusion through sheer physical action, but Irving Reis elected to direct in waltz tempo.

O'Brien was convincing as the pig-headed unconscious American who has modern technology work for him and against him, as the inventions from the war are now shared by both criminals and scientists.