Twenty-five years ago there was a great interplanetary war in the Solar System. It was a suicidal spasm in which terrible weapons were created and used; in which nine billion people were killed. The rivalries that led to the war are not gone. And a few of those deadly weapons remain—some still orbiting the sun in the debris of destroyed ships, some deliberately placed in storage.

Now Cyrus Mobarak, the man who perfected the fusion engine, is determined to bring human settlement to the protected seas of Europa. Opposing him is Hilda Brandt, Europa's administrator. And caught between them are three remarkable young people: Jon Perry, Camille Hamilton, and Wilsa Sheer.