By Andre Alice Norton

“Travis Fox encounters the heroes of the previous story so near to the beginning of a secret mission that he is taken along. While looking for a crashed alien ship in the past, they discover another still in working condition. During an emergency, they take shelter inside, but are trapped when the ship leaves on an automatic course. The craft’s final destination is a ruined city of an advanced civilization. They meet primitive locals who want them to explain the abandoned artifacts, and whom they help with weapons to defend themselves. Finding technology similar to the ship’s, they experiment on it, and are able to direct the ship back to Earth.” ~ Wikipedia