Enthusiast is the sixth book in the Tom Walker mystery series, introducing Sarah Logan as a fellow traveler. This mystery starts with Sarah having to make her own way in her teenage years after her dad dies and her mother leaves for another life. Sarah pulls herself up by her bootstraps to avoid being sent to foster care. She leverages the little bit of property left to do this. Her ninth-grade English teacher, Joan Barker, spots her as a promising student and a person to dispose of her blackmailer, one way or another. Sarah takes on the task and the adventure is afoot. The results have a touch of Sue Grafton, Dick Francis, and Patricia Highsmith, but perhaps primarily Thomas Perry.