A borrowed man

Gene Wolfe

It's perhaps a hundred years in the future and E. A. Smithe 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". Colette Coldbrook "decides to check Smithe out from the library because he is the surviving personality of the author of Murder on Mars", and the physical copy of the same book was in the possession of her father when he disappeared and presumed dead.--