A six-man spaceship returns from the Pegasus Star System and encounters turbulence while passing through a wormhole. Their ship is damaged and they are forced to crash-land on Earth in the year 1942. World War II rages while they attempt repairs on their ship. They cannot use their technology to defend themselves because it would risk altering their own future. They are forced to take on false identities and enter Nazi-occupied territory where they encounter problems that threaten their chances for success. Hitlers SS intends to find them and capture their technology, an alien mind-controlling presence that returned with them from deep space plans to conquer Earth, and one crew member falls in love with a beautiful Jewish engineer held prisoner on an airbase near Berlin. She is considered the personal property of a jealous, high-ranking Nazi. Time is running out and Earths future depends on their returning to their time.