One Mysterious Night

The Blue Star of the Nile is stolen from a guarded exhibition, throwing Farraday's police unit into a high-pressure scramble to recover the jewel. In a bid to look decisive, Farraday publicly accuses Boston Blackie of the crime, though he privately suspects Blackie is innocent. The theatrical accusation sets the tone for a convoluted pursuit in which Blackie is pressed into action.

To salvage the situation, Farraday deputizes Blackie to recover the diamond, using his own rough methods as cover. He makes clear this is a ruse to flush out the real thieves, not a confession of Blackie's guilt. Blackie accepts, eager for a chance to flip the narrative and clear his name.

Blackie combs the crime scene and discovers a wad of gum bearing the diamond's impression, a clue that points to an inside job. Learning that George Daley, the assistant manager, had recently bought a lot of gum, Blackie focuses his suspicions on him. The lead shifts the hunt from an outside thief to someone with access inside the exhibition hall.

Dorothy Anderson recognizes Blackie at the station and has him arrested, only for Farraday to spring him through the back entrance. The maneuver demonstrates Farraday's willingness to bend procedure for Blackie's cooperation. Blackie continues the pursuit with the trail growing colder outside the police walls.

Daley's sister, Eileen, learns her brother is entangled with thieves and that the diamond was hidden in her purse. She pressures Daley to pass the jewel to Blackie, hoping to salvage the situation or profit from the exchange. The move sets up a critical handoff between Blackie and the criminals.

Daley's former partners arrive just after Blackie meets him, triggering a scuffle in which Daley is killed. The criminals kidnap Blackie and his sidekick, the Runt, to ensure Blackie's silence and a quick frame job. The case grows darker as the murder and disappearances complicate the police narrative.

With Blackie missing and the murder on record, Farraday begins to believe Blackie may be responsible for both the robbery and the murder. The implication strengthens the police drive to rid the city of Blackie's influence, even as the truth remains unclear. The manhunt tightens around Blackie and his associates.

Blackie tells his captors that the object in their possession is a fake arranged for a switch with the real diamond stored in a vault. They take the fake to fence Jumbo Madigan to confirm the story. Blackie bets the lie will buy him time and a chance to outsmart the crooks.

Blackie frees himself and the Runt and convinces Madigan to go along with the ruse. When the police close in, Martens and Healy realize they've been double-crossed and shoot Madigan, though not fatally. The crooks then disguise themselves as mannequins to avoid capture as the cops sweep the room.

The thieves return to their apartment, where Blackie proposes stealing the real diamond himself, with the Runt held as a hostage to seal the deal. The plan heightens the stakes for everyone as time runs short. The arrangement marks Blackie's willingness to take extreme steps to resolve the case.

Blackie goes to Farraday, who surrounds the building with police, and the two men enter the apartment to negotiate the Runt's release. The uneasy alliance between law and trickery bears down on the criminals in a tense final confrontation. Blackie's improvisation and Farraday's leverage push the case toward a resolution.

Martens and Healy attempt a last-minute breakout but are quickly caught, ending their bid for escape. The police close the net as Blackie and Farraday secure the diamond's return and the Runt's safe release. The case concludes with the criminals in custody and the jewel recovered.