The holdup of the bank is a success. All happened according to plan. Now, Cyril Gad and his four accomplices must secure an alibi. What better place than a prison cell? As a result the five gangsters have themselves arrested on minor charges and start waiting until they are released. Unfortunately three of them die mysteriously, another one is openly murdered. The only man still alive, Tony, is scared. Easy to understand why...
The charming Lulu, a cabaret singer and dancer, has no shortage of admirers. When she decides to get married, she sets her heart on Robert, a young industrialist, but he is already married. Disappointed, she sets out in search of the ideal man.
To protect him, Georges takes the place of his twin brother, Jacques, suspected of murdering an aircraft manufacturer and stealing the plans for a revolutionary engine. He sets out to compromise the police investigation and the actions of the document smugglers seeking to recover the plans.
