Hull Zero Three

He wakes with no name, no clothes and no memory, on a starship where the gravity keeps changing direction and the temperature swings between freezing and unbearable. A small girl finds him, calls him Teacher, and leads him through a maze of torn corridors while something mechanical works its way toward them.

The other survivors they gather are as confused as he is, and as specialised: each of them built for a role in a crew that no longer exists in the form anyone intended. He is a clone. He has been made and killed before, more than once, and previous versions left notes.

Greg Bear writes hard science fiction as a horror puzzle here: a closed ship, an amnesiac narrator, and a mission whose original purpose has been fought over so long that both sides of the argument are now walking around in bodies grown for the job.