The film tells the fictitious story of a German U-Boat, sent from Norway to Japan to carry secret plans to build an atomic bomb. A huge amount of Uranium oxide also is on board. The crew is joined by an air force general, a military judge and two Japanese officers. This is why spies from Norway take notice of the plan. The port of destination is Tokio, because this is the last way to Hitler's allies. In Japan the chance to build the bomb is much better than in Germany. The atomic bomb is the last hope to make Germany win the war, but Hitler's suicide and the German capitulation make the plans fail and cause conflicts on board of the U-Boat.