Wolfe also wrote many stand-alone books. His first novel, "Operation Ares", was published by Berkley Books in 1970 and was unsuccessful. He subsequently wrote two novels held in particularly high esteem, "Peace" and "The Fifth Head of Cerberus". The first is the seemingly-rambling narrative of Alden Dennis Weer, a man of many secrets who reviews his life under mysterious circumstances. "The Fifth Head of Cerberus" is either a collection of three novellas or a novel in three parts, dealing with colonialism, memory, and the nature of personal identity. The first story, which gives the book its name, was nominated for the Nebula Award for Best Novella.