A U-boat. The Pacific Ocean. And a mysterious book deemed illegal by the Nazi party, turning up in odd places around the ship. No matter how many times the sailors throw it into the ocean...

Young radio operator Udo Grotendick has his work cut out for him when he is assigned to a U-boat stationed in the middle of the Pacific Ocean. The captain and its crew have a fearsome reputation as the most brutal crew of the German Kriegsmarine, and Udo is keen to join the war effort, even as World War 2 draws to a close. But, things do not go to plan when he is caught with a book banned by the Nazi party! However, this book seems to have a personality all of its own... Every time it is thrown into the ocean, it reappears! Will this mysterious book, and the unforgiving conditions at sea finally be the end of this brave crew?