The machine was given three commands: Keep Amy alive, safe, and happy. The first two were easy enough, but the third meant understanding humans far better than they did themselves.

When most of their crew is killed by an explosion on the ship, Mason fights to stay alive long enough to program an artificial intelligence to save his daughter. They are four and a half light years from Earth and rescue is not a possibility. As he begins to hallucinate from carbon dioxide toxicity, he overwrites the directives of the AI until he has installed a primary command structure. The AI he has called Neumann must ensure that Amy is alive, safe, and happy.

As he slips into unconsciousness, Mason little realizes the machine's capabilities and how firmly he has installed his orders. Going far beyond a human guardian, the AI rigidly carries the directives to their logical conclusion. As far as Neumann is concerned, Amy must stay alive despite the ship deteriorating around them, and be kept safe from the debris field of the explosion and cosmic rays. When those goals are fulfilled, the machine wrestles with the nebulous notion of human happiness.

Reacting as a machine might be expected to, Neumann solves problems humans have suffered from for centuries, and creates others that even a child could have avoided. With the girl's life in his resourceful hands, Neumann is prepared to do anything to ensure her survival. While Amy hibernates, Neumann rallies the immense resources of a solar system so that she will have everything she wants or needs when she wakes.