Based on two scientific discoveries, Galaxy Enterprises secretly constructs a new concept space ship on Earth. Concurrently, they financed a pair of college students to form the nucleus of a six month, locked-in, shakedown crew, who put the ship through simulated tests, while the real crew trained for space. Before the end of the mock flight, a competing corporation's army invades the site to steal the ship. To avoid capture and the loss of the ship, the pilot launches. While trying to avoid being shot down, the crew end up thirteen light-years in space, where they become the alien intruders. They must avoid capture and try to get home.