The book was Mason's first novel; he had previously written a memoir about his experiences in Vietnam titled Chickenhawk.

The book is about an android, designed to kill, which experiences a crisis of conscience and runs away from its government masters to live in a Nicaraguan village.

Most importantly, Solo is governed by a neural network computer which is able to learn and think much as a human brain does.

On another training mission Solo is lost; he is discovered by a group of Nicaraguan villagers who although initially fearful of him, come to trust the robot and depend on his protection.

It was adapted to film as Solo in 1996, taking the name of the main character and title of the sequel novel released in 1992.