U-900 plot
The year is 1944 and the Second World War is gradually coming to an end. The German General Staff wants to send the last available U-boat, the U-900, on a secret mission, namely from Toulon to Warnemünde. When Atze Schröder comes into contact with the person responsible for this assignment, General Strasser, he has to flee together with a certain Samuel and Maria. The trio hijack U-900, with Atze impersonating the legendary 'Captain-Lieutenant Rönburg'. Even if he didn't like seafaring at all, Atze wouldn't be Atze if he didn't have a solution for every problem. But a while later, the submarine's crew becomes suspicious, as their Captain-Lieutenant is constantly giving unconventional orders...