Book excerpt: "For the teachers and students of Seattle's Garfield High School, the trip was just a public-relations lark, for helping a wealthy Pacific island open a science museum, they were to get a free trip around the world. It all seemed too esay. It was. As their chartered 747 crossed the Pacific, a huge spacecraft swooped down, cut off its wings, swallowed it up, and headed deep into outer space. Next stop: Charon, the moon of Pluto. Suddenly the flight crew, the students, and their teacher found themselves the unwilling guests of unseen and unreliable hosts whose life-support systems were breaking down. Even worse, the humans were caught in a deadly cross-fire between the rapidly failing aliens and a mad computer program that considered only itself indispensable, and whose intentions clearly were to destroy Earth ..."--Page 4 of cover