CIA agent Harry Wargrave is sent to aid Gen. Marenkov, a senior Russian official, who is defecting to the west. Wargrave decides they should travel to safety on a train across Europe, the "Atlantic Express". During the journey, they must survive attacks by terrorists and an avalanche, all planned by Russian spy-catcher Nikolai Bunin.

A fur-trapper battles the elements and robbers when a gold shipment is ambushed - leaving a boy in urgent need of medical attention.