The Circus Queen Murder

Colt, the New York Police Commissioner, decides to take a vacation after six years of fighting crime. He travels with his attractive secretary Miss Kelly. On the train to their destination, they spot a rundown circus—the Greater John T Rainey Shows— heading to the same place.

The circus parades through town and catches Colt's eye. Dugan, the circus press agent, recognizes his old friend and secures free passes for Colt and Miss Kelly. The troupe is defined by a love triangle among Josie La Tour, her husband Flandrin, and her lover The Great Sebastian, all trapeze performers.

Dugan takes Colt to see Rainey that evening; Rainey warns that someone aims to destroy his show. Each principal performer has received an anonymous note threatening death if they perform on Friday the 13th. Colt suspects the threat might be a publicity stunt orchestrated by Dugan.

Rainey reveals La Tour owns half the circus, intensifying motives and danger. A note promises 'first to go' for Flandrin, a bullet hole is found in his wagon window, and there is blood on his cot, though no body is present yet. The mystery deepens as the threat profile expands to the entire troupe.

La Tour's beloved dog is found with its throat cut, signaling violent intent. A voodoo doll is thrown through her window, adding a sinister, theatrical touch to the threats. Colt grows more suspicious that the danger is closer to home than a mere publicity stunt.

Kelly reports that the blood is not human, suggesting a non-human source. Colt notices an extra member of the so-called cannibal troupe last night, with Flandrin in disguise among them. The investigation points away from ordinary murder or sabotage.

Outside the audience, Flandrin climbs to the top of the Big Top. During a stunt, one trapeze rope is partially cut, nearly causing Sebastian to fall. The crowd believes it is all part of the night's act, masking a deliberate sabotage.

La Tour performs on the trapeze when Flandrin shoots her with a poison dart from a blowgun. She collapses and dies, leaving the audience unaware that a crime has just occurred and the killer remains at large.

While Colt roams the grounds, Flandrin captures Kelly and forces Colt to ensure that Sebastian is alone with La Tour's body. Colt plays along, hoping to prevent further harm while continuing his investigation from inside the trap.

Colt dons a belt and bulletproof clothing borrowed from the circus and enters the tent in disguise. He brings Kelly with him as Flandrin manipulates the scene, and Flandrin shoots Sebastian in the back, presumably removing a rival.

Racing to his final performance high in the air, Flandrin shoots himself at the finale. Colt and Kelly survive the ordeal, and the dangerous thread of the circus plot is finally severed.