Yellow Canary

During a bombing raid over London, Sally Maitland signals Nazi planes and murders an innocent civilian. The act establishes her as morally ambiguous and reveals her apparent admiration for Nazi Germany.

The morning after the London raid, Sally boards a transatlantic liner bound for Canada. On board, Jim Garrick and Jan Orlock take an interest in her, though the true motive of both men remains unclear.

Jim Garrick, a British intelligence officer, and Jan Orlock seek Sally's acquaintance despite her Nazi sympathies. Sally pretends to engage with them while secretly shadowing Jan as the target of her mission.

A boarding party from the German heavy cruiser Prinz Eugen halts the liner, and Jim is briefly taken prisoner. It is revealed that an impostor has been captured, and Jim steps from hiding to reveal his true undercover role.

In Halifax, Jan introduces Sally to his invalid mother, Madame Orlock. Jim leverages his contacts to present Sally as a genuine Nazi sympathizer and warns the Orlocks to stay away, while Sally pretends to distance herself to protect them.

That night, Jan reveals he is working for the Nazis and recruits Sally into his spy ring. Sally hopes to uncover the conspirators and identify the ring's leader, who turns out to be Madame Orlock.

The conspirators reveal a plan to substitute a ship in an incoming convoy with one loaded with explosives, to detonate on reaching Halifax and wreck the vital port. The scheme echoes a disastrous First World War accident.

Jan explains a bungled secret mission to bomb British royalty that failed because of incorrect landmark signals, which ties to Sally’s earlier kill of a Nazi agent and thwarting that mission.

Sally catches Jim breaking into Jan's study to uncover evidence, realizing he has been assigned to watch over her as part of the mission. The revelation complicates their uneasy alliance.

Orlock sneaks into Sally’s room; Sally claims she’s tricking the enemy and narrowly avoids execution. She slips Jim a lipstick-note advising him to wait at headquarters for information and leaves with Orlock.

Orlock orders Sally to phone Jim and warn him that a sabotage attempt will target the Queen Mary; naval intelligence is alerted and dispatched to stop it, with RCMP and RCAF involved.

During the confrontation, Jan shoots Sally; Jim rushes to rescue her, and the bullet is stopped by a cigarette case he had given her earlier, saving her life and deepening their bond.

After the events, Sally’s cover is blown but she and Jim marry, and they return to London to meet her family, closing their wartime journey with a personal reunion.