In 1942, journalist Manning (Loder) arrives at an English air base to learn about the Free French who are fighting the Germans. Manning's interest focuses on Jean Matrac (Bogart), a gunner, and Captain Freycinet (Rains) describes Matrac's story: Two years earlier, just before the defeat of France by the Germans, five convicts, led by Matrac, escaped from the prison colony of French Guiana and are found adrift in a small canoe in the Caribbean Sea. When they find out about the situation of the war, they decide to join the forces against the Nazis.
Max Steiner composed the music.
This film features examples of:
- Action Prologue: Starts with an action sequence featuring a Free French Air Force squadron on a bombing raid.
- The Alcatraz: French Guiana, a horrific, brutal penal colony where the workers perform backbreaking manual labor and die like flies. Even the "free" people who complete their sentence aren't allowed to leave the colony.
- Ask a Stupid Question...: When the escapees make their rendezvous with Grandpere, he sighs with relief and says "You made it." Marius shoots back with "No we didn't; we are still in the barracks."
- The Big Board: Freycinet has a map up on his wall of Western Europe, centered on France.
- Captain Obvious: As they rest by the riverbank the escapees conclude that "we are one too many" to make the open sea, since their canoe is sitting so low in the water. For some reason, Matrac is compelled to draw "6-5=1" in the dirt to underline this point.
- Cold Equation: The escapees observe that their canoe sits very low in the river and that they will for sure be swamped when they hit the open ocean. So one of them has to stay behind. Grandpere picks himself, he being the only one who is too old to fight for France.
- Everyone Calls Him "Barkeep": The old former prisoner who provides the canoe and organizes the escape from Guiana is called "Grandpere"—Grandpa.
- Eyepatch of Power: How do we know Capt. Freycinet is a badass? He has an eyepatch.
- Flashback: A reporter comes to an air base to interview a Free French officer, who starts telling the story of one of his men. Flashback to the man being recovered at sea by a ship along with four others. It is revealed that they are escaped prisoners. Flashback to them planning to escape in order to join the fight against the Germans...
- Flashback Within a Flashback: The first flashback is Freycinet telling the story of how the escaped convicts were plucked from a raft. Within that there's a flashback to Matrac and the other convicts escaping from Devil's Island. Within that there's a flashback to how Matrac went to Devil's Island in the first place, namely, framed for murder due to his inconvenient newspaper reporting.
- Frame-Up: It is revealed that before the war, Matrac was a crusading journalist opposed to the Munich Pact, and was framed for murder to shut him up.
- Framing Device: A war correspondent arrives at a Free French Air Force squadron based in England. He expresses curiosity about Matrac, which leads Freycinet to tell the whole story.
- Great Escape: The group of convicts led by Matrac escape French Guiana by raft.
- It Will Never Catch On: All the officers aboard the tramp steamer that Freycinet is taking back home are blithely confident that the Maginot Line renders France invulnerable. Only Freycinet has the intelligence to point out what might happen if the Germans go around the Maginot Line.
- Match Cut: From Garou chopping a tree to Marius whittling a stick, as the film cuts from the second flashback back to the first one.
- The Mutiny: Major Duval leads the engine room crew in a mutiny, and announces that he will be taking the ship back to Vichy France. It's short-lived as Capt. Malo and the loyal crew fight back and defeat the bad guys.
- Spiritual Successor: To Casablanca. That film, which was a massive hit, was about La Résistance, and ended with Rick and Louis going off to join the Free French. This film is about people fighting with the Free French, with the same director, and with six actors from Casablanca in the cast.note
- Torches and Pitchforks: An angry mob wrecks Matrac's little newspaper business after Matrac criticized the Munich Accord.