A technician falls under an alien influence, accessing classified information before mysteriously dying. Soon after, the Moon is stopped in space by the powerful rays of an alien spacecraft. The aliens' only interest in Alpha is the data held in its computers, information they now plan to obtain through the possessed eyes of their next agent: Helena Russell.

John Koenig finds himself trapped on the planet Zenno, in the home of an alien scientist and his daughter. Advanced two million years beyond Earthmen, the aliens consider Koenig their missing link. Faced with the threat of being treated like an experimental animal for the rest of his life, Koenig uses an unexpected weapon to confound his captor: love.

The Moon approaches a solar system with two planets on opposites sides of its sun. The Alphans are trapped in an interplanetary conflict when warships from both worlds trespass on the Moon to fire missiles at their opponents' planets. After taking in a refugee from a destroyed gunship, the Alphans discover they have drifted into the middle of a literal war of the sexes.