American Mystery Classics, July 2019 (original publication 1942)
Police Detective Lt. Terence Marshall, of the Los Angeles Police Department, is home with his wife, Leona, feeding their new baby, while she asks about his day. Nothing interesting, he tells her. One dead drifter, though, shot dead in a very cheap hotel. A couple of odd things, though. He had $300 on him, that wasn't stolen, and an unusual rosary, with what seems to be the wrong number of beads.
It's a puzzle.
It's a bigger, more important puzzle, when they discover the dead man also has the private phone number of Hilary Foulkes, heir and literary executor of the late giant of science fiction, Fowler Foulkes, author the adventures of Dr. Derringer. Derringer has outlived Fowler, or would, if not for the fact that Hilary Foulkes charges extremely high fees for any use of Derringer's name, image, or adventures. He's killed many literary projects, original adventures, quotes of memorable lines as chapter headers, even audio records for the National Library for the Blind. A lot of people really hate Hilary Foulkes.