1944年德国法西斯在战场上节节失利,德国将军斯特拉瑟意外找到了传说中的耶稣圣杯,德国指挥官们认为有了圣杯就能战胜一切,但是却面临着如何将万里之外的圣杯运回德国总部的问题,因为美国为首的同盟国将不惜代价阻止他们,斯特拉瑟将军想到了用U-900号潜艇将圣杯偷运回国,然而却被一个向往美国的德国人、一个犹太人和一个不得志的女演员意外将计划打乱········It is the year 1944 and World War II is not over yet. The Germans want to send their last available submarine, the U-900, on a secret mission from Toulon to Warnemuende. Atze pretends to be the legendary Lieutenant Commander Roenberg. But the crew gets suspicious when their commander starts issuing unconventional orders.