Cambridge mathematician Andrew Martin has finally cracked the Reiman Hypothesis. Sentient creatures on the planet Vonnadoria are alarmed, believing that this will now give the human race the power to discover other worlds and develop travel throughout the universe.  But because they despise the human race, they cannot let such power fall into such hands. One of their creatures immediately travels to earth, kills Andrew Martin, and takes over his body.  It is his task to destroy the proof he developed (for the Reiman Hypothesis) and kill his family and others who have knowledge of it. 

Smart as the Vonnadorians are, the new Andrew Martin has trouble getting the hang of things like wearing clothes, eating food, and handling women and teenagers.  Coming from an emotionless planet, he was unprepared for human emotions, the good and the bad.  

Haig’s story does a wonderful job of making us think about both the blessings and curse of being human.  Some worthy insights pepper the book.  And the reader is taken along for a ride through a clever and suspenseful story.