Based closely on Dashiell Hammett's novel, a detective's partner is killed, and he finds his killer and a conspiracy that murdered two others too.
In San Francisco Miss Wonderly (Mary Astor) hires detective Sam Spade (Humphrey Bogart) to find her sister and get her away from Thursby. Sam's partner Miles Archer (Jerome Cowan) goes but is shot dead. Sam tells his secretary Effie (Lee Patrick) to tell Miles' wife Iva (Gladys George). At the murder scene police detective Tom Polhaus (Ward Bond) shows Sam the gun. Police Lt. Dundee (Barton MacLane) and Tom come to Sam and tell him that Thursby was shot in the back. Sam finds Iva in his office and kisses her. She asks if he killed Miles and cries. Effie suspects that Iva killed Miles. Miss Wonderly calls, and Sam goes to her, learning she is Brigid O'Shaughnessy as she admits she lied. She says Thursby killed Miles. Sam has her give him $500. Sam consults his lawyer by phone. Joel Cairo (Peter Lorre) comes in and offers him $5,000 for a bird statue. Cairo with a gun wants to search; but Sam knocks him out and goes through his pockets. Sam gives him his gun back, and Joel again demands to search.
Sam loses a man tailing him and goes back to Brigid, saying Cairo wants the bird and kissing her. They go to his place, and Cairo comes in. Brigid says Thursby had the falcon, and she can get it. Sam stops Cairo from pulling a gun and slaps him. Tom and Dundee question Sam, who denies being involved with Iva. Cairo shouts that Brigid attacked him. Sam explains, and Dundee hits Sam but does not arrest him. Brigid tells lies to Sam. In a hotel lobby Sam has Luke make his tail leave. Cairo tells Sam police questioned him. At his office Sam asks Effie to put up Brigid. Iva asks Sam to forgive him for sending the police.
Sam calls on the fat man, Kaspar Gutman (Sydney Greenstreet) and asks about the bird. Sam threatens to kill his tail Wilmer (Elisha Cook Jr.), calling him a "gunsel" (Yiddish slang for homosexual) and stalks out. The district attorney questions Sam, who says he must catch the killers to clear himself and leaves. Sam takes Wilmer's guns and hands them to Gutman in his apartment. Gutman says that in 1539 Malta knights sent a golden falcon to Spain, but it was stolen and painted black. Gutmann says his agents got it and offers Sam $50,000 or a fourth for it. Sam is drugged and collapses, and they leave. Sam recovers and tells Effie what happened. Captain Jacobi staggers in, drops a bundle, and dies from bullet wounds. Sam sees it is the bird. Effie gets a call that Brigid is in danger. Sam tells her not to mention the bundle and checks it as luggage, mailing the ticket.
Sam finds Brigid, and at his apartment they find Wilmer, Gutman, and Cairo. Gutman gives Sam $10,000. Sam says they need a fall guy for the murders and suggests Wilmer, then Cairo or Brigid. Sam knocks out Wilmer and takes his guns. Gutman says that Wilmer killed Thursby and Captain Jacobi so they could get the falcon. Sam calls Effie to get the bundle, and she brings it. Gutman uncovers it and says it is fake. Wilmer is gone. Gutman gets $9,000 back as Sam keeps $1,000. Sam calls Tom to get Wilmer, Gutman, and Cairo. Sam accuses Brigid of shooting Miles and says he won't be a sap for her; but he wavers and kisses her. Dundee and Tom arrive, and Sam turns her in for murder.
Gutman speaks with sophistication; but the four criminals
are greedy fools caught by the clever detective, who is able to
take a gun away three times even after announcing his intention
to do so (only in the movies). Credited with helping to initiate
the film noir, this detective story has great style and a tight