Major Wright and the Dirty Dozen are given a unique assignment by General Worden - the destruction of a group of top-level Nazi military, scientific and political leaders. Hitler's plan is to send this group to Istanbul, Turkey where they will establish a new Fourth Reich and return to power even if Germany loses. World War II. Wright learns that his quarry is travelling to Istanbul on a special train that in peacetime was part of the luxurious Orient Express and now is heavily guarded by the dreaded Waffen SS. After one of the soldiers is mysteriously killed during a training session, a spy is suspected among the Dirty Dozen. Under extreme time pressure, the Allied High Command agrees with Wright that he must proceed with the plan, locate the traitor in their midst and dispose of him along the way. U.S. Lieutenant Carol Campbell, with ties to German Intelligence, has volunteered to join the group in their mission. The action move to Yugoslavia and the Balkans and culminates in a spectacular assault on the train, then an all-out race to the Greek coast with Hitler's possible successor attempting to intercept and destroy the Dirty Dozen.