Set in turn-of-the century London, this period thriller stars Laird Cregar as George Harvey Bone, a composer who suffers from a rather severe case of artistic temperament. Driven to distraction by the discordant sounds of the city, the usually sensitive Bone occasionally snaps when exposed to undue stress, and the results can be deadly; he sometimes blacks out and commits murders that he can't quite recall the next morning. Working on a major concerto, Bone is at his wit's end, and when an antique dealer tries to cheat him, the salesman turns up dead. Dr. Allen Middleton (George Sanders), a psychologist with Scotland Yard, questions Bone about the crime; he claims to know nothing about it, but the perceptive doctor suggests that Bone needs to relax more. Taking Middleton's advice, Bone visits a music hall that evening and sees Netta London (Linda Darnell), a singer with whom Bone immediately becomes entranced. This makes the composer even less patient with his sweetheart Barbara Chapman (Faye Marlowe), whose father, the wealthy Sir Henry Chapman (Alan Napier), has commissioned Bone's latest work. When Barbara tells Bone that his concerto is not up to snuff, she only narrowly escapes with her life, and while Bone believes that he's found true love with the beautiful Netta, the singer finds herself in danger when Bone suspects her of infidelity. Hangover Square gave character actor Laird Cregar his first starring role. Sadly, it was also his last film; Cregar, who struggled with weight problems all his life, tipped the scales at nearly 300 pounds when he made this film. Eager for more starring roles, Cregar went on a dangerous crash diet, and while he soon lost 100 pounds, it put his health into serious disarray, and the actor died of a heart attack at the age of 28, shortly before the release of his first starring vehicle.