Murphy is the sole survivor of his crew, that has been massacred by a German U-Boat in the closing days of World War II. He lands on the shore somewhere on the river Orinoco delta and begins to plot his vengeance. He wishes to sink the U-Boat that has floated up by means of any method imaginable to him, and sets about to make the courageous attempt, assisted by Louie, the islands Government Administrator.

In the closing days of World War II, German prisoners riot in a POW Camp in Scotland. Fearful of a mass escape attempt, the British Army sends in an unorthodox Irish Captain in hopes of discovering exactly what is going on. The Irishman at once comes into conflict with the senior prisoner, a U-Boat commander, and the two must match wits, knowing that only one will emerge victorious.