When aliens emerge from the walls and neutralize everyone on the space station but Gordon, he travels back in time in an experimental time machine to stop the alien invasion, but accidentally ends up five years in the past.

"Agent Gordon's distress calls to P.U.R.S.T. (Pets of the Universe Ready for Space Travel) have gone unanswered. His humans and fellow agents have been captured! He is all alone in the middle of an alien invasion! Gordon's deadliest weapon is his mind, but none of the computers, robots or other devices he's built could have prepared him for this. Or could they ...? Gordon has an idea. But is it too dangerous? The device isn't ready--it's just a prototype! Doggone it, Gordon needs more time!" -- Back cover.