E.A. Smithe is a borrowed person. He is a clone who lives on a third-tier shelf in a public library, and his personality is an uploaded recording of a deceased mystery writer. Smithe is a piece of property, not a legal human. A wealthy patron, Colette Coldbrook, takes him from the library because he is the surviving personality of the author of Murder on Mars. A copy of the book was in the possession of her murdered father and it contains an important secret, the key to immense family wealth. Her brother turned up dead after giving the book to her. Now the book is lost, and Colette is afraid of the police. Smythe is her last hope. She borrows Smithe to help her find the book and to find out what the secret is. Together they find something almost anyone would kill for.