Mr. Big has spent several days timing the arrival and departure of an armored car to a bank and a delivery truck to the florist next door in order to plan a robbery of the armored car. He recruits three criminals for the robbery: Pete Harris (Jack Elam), Tony Romano (Lee Van Cleef) and Boyd Kane (Neville Brand). While meeting all three, Mr. Big wears a mask to disguise himself. He tells all three that they will also wear masks during the robbery, to hide their identities from each other, so that they can't tell anything to the police about Mr. Big or the other robbers if they get caught. The plan for the robbery is simple: wait until the delivery truck drives away, then drive up to the armored car with an identical delivery truck and attack the security guards when they walk out of the bank with the money. The plan goes perfectly and the criminals steals 1.2 million dollar. After the robbery, Mr. Big gives each robber a torn king playing card, some money and tells them to lay low in other countries, awaiting further instructions about dividing the money.
Meanwhile, the delivery truck driver, ex-con Joe Rolfe (John Payne) gets arrested and accused of the robbery. He is eventually released after several weeks of rough interrogations, when the other delivery truck used in the robbery truck is found. Having lost his job, Joe decides to find the criminals and clear his name.
Tropes:
- Aside Glance: A prolonged one from Diaz, the taxi driver that drives Joe Rolfe around Tijuana. It's almost as he is addressing the audience when he says that gambling is illegal.
- Big Bad: Mr. Big, the mastermind behind the robbery.
- Bilingual Bonus: The name of the boat in which the stolen money are hidden and the final confrontation takes place is "Mañana", meaning "tomorrow" or "morning" in Spanish depending the context in which it is used.
- Clear My Name: Joe Rolfe's character arc is him hunting down the thieves to clear his name with the police (and everybody else who thinks it was an Inside Job).
- Dead Person Impersonation: After Pete Harris is killed at Tijuana Airport, Joe decides to impersonate him.
- Gun Struggle: Whenever a character draws a gun, he will pretty much lose it in a struggle.
- Malevolent Masked Men: All four robbers wears cloth masks to hide their identities from each other.
- Masquerading As the Unseen: After Joe encounters Pete Harris, one of the thieves, in Tijuana Airport and sets off a chain of events that get Pete killed, Joe decides to impersonate him and go to the rendezvous to collect Pete's part of the loot (and the other thieves are going to), hoping that the fact only Mr. Big knows Pete will help him.
- No Honor Among Thieves: Tim Foster (Mr. Big) planned from the beginning to turn the other criminals over to the police to get the reward. Romano also kills Kane and planned to kill Joe to get more money.
- Police Brutality: Heavily implied that the police tries to beat a confession out of Joe.
- Reformed Criminal: Joe Rolfe. Unfortunately, this detail of his backstory is precisely why the police thinks he is onto it.
- Reluctant Retiree: Tim Foster was forced to retire from the Kansas City Police for political reasons.
- Run for the Border: All criminals involved in the robbery flees the country. Pete Harris escaped to Tijuana, Mexico.
