Survivors from a torpedoed passenger vessel are rescued by a lighthouse crew. Ironically, the German captain responsible for the attack is also rescued and held prisoner, but a spy among the survivors plans to help him escape.
A group of survivors in a lifeboat from a torpedoed neutral ship on its way to Portugal pick up a seventh survivor - Austin Trevor (Captain Hatzmann). He is the captain of the U-boat that is responsible for the sinking of the ship and he guides them to a lighthouse from which he intends to escape back to the Fatherland. The story unfolds at the lighthouse as we wait for help to arrive and take Trevor away to safety. However, amongst the stranded passengers are a British agent and a Nazi spy as well as a couple of tricksters. Who is who.....?
The film is a mystery as we try to guess who the British agent is and who the Nazi spy is. It keeps us guessing and despite the limited cast, it does a very good job of concealing the truth. You won't guess the outcome. There are also amusing sections of dialogue that you should enjoy, eg, Ronald Shiner (Ernie) and his use of the term "dago" and Austin Trevor's rather frank announcement that he hates the Dutch. It's quality stuff.