Shadow of Doubt

Sim Sturdevant visits his aunt Melissa Pilson and faces her anger over his affair with Trenna Plaice. Pilson accuses Plaice of social inferiority and being after money, and she makes her disapproval clear. Sturdevant insists he plans to marry Plaice and has secured a radio contract to support her career in New York.

Plaice declines Sturdevant's marriage proposal, noting a film offer and a rival proposal from Len Hayworth. The two argue, and Plaice calls Hayworth to accept his proposal. Immediately after Sturdevant leaves, Plaice receives a call from Lisa Bellwood claiming she will marry Hayworth the next day.

At a club, Sturdevant offers the radio contract to singer Johnny Johnson. Len Hayworth and Lisa Bellwood arrive, triggering Johnson's jealousy since Hayworth has made advances toward Bellwood. Reed Ryan, Johnson's boyfriend and press agent, approaches Sturdevant's table, and Hayworth tells Ryan about Sturdevant's failed proposal, leading to a punch-up between Sturdevant and Hayworth.

Hearing a rumor that Hayworth wants revenge for his humiliation, Johnson follows Hayworth home from the club. At the same time, Plaice visits Hayworth's home, where she is admitted by a butler who tells her he needs to go out, but she can wait for Hayworth inside.

Bellwood brings home Hayworth, who has passed out drunk, and leaves him on a couch, not realizing that Plaice is in the next room. Soon after, Hayworth's butler returns and finds him dead on the couch from a gunshot wound.

The police suspect Plaice because she admits to being in Hayworth's home, and she also previously owned a pistol of the same type used in the murder, though she claims to no longer have it. Plaice explains she went to Hayworth to turn down his proposal in favor of Sturdevant, which heightens scrutiny of her alibi.

Hayworth's butler calls claiming to know who committed the murder. When Plaice goes to meet the butler, he is killed by an unknown shooter, using the same type of gun that killed Hayworth. The murders deepen the mystery and broadens the circle of potential suspects.

Pilson visits Plaice and, seeing her distress, decides Plaice is innocent. She discovers a pistol hidden in Plaice's apartment and removes it before the police can find it. Pilson then schemes to trap the killer by publicly claiming she has located the thief who sold the gun and will have him testify.

The killer is revealed to be Reed Ryan, who was jealous of Hayworth's attention to Johnny Johnson. As a Hollywood memorabilia collector, Ryan had previously purchased the stolen gun from Plaice's former butler and used it to divert suspicion away from himself. The revelation ties the gun to Ryan's motive.

The link between the gun, Plaice's former butler, and Ryan is confirmed, explaining how the weapon circulated and allowed Ryan to manipulate the investigation. Pilson's public trap underscores the gun's true origin and who profited from the theft. The evidence finally closes the circle on the crime.

With Ryan identified as the killer and the gun's provenance established, Plaice is cleared of suspicion and the case reaches its conclusion. The police wrap up the investigation, and the involved parties confront the consequences of their actions. The truth is finally exposed.