Cosmos Desoto and the Search for Gomez Moxley — Michael de Guzman

The second book in this series has Cosmos DeSoto, private detective, handling two cases at the same time; the search for the author, Gomez Moxley, and tracking down the blackmailers who are after the movie star, Symphony Fairchild. In his real life, Cosmos and his mother travel by train to New Mexico to visit Hank and Hasty. A journey that changes both their lives.