Beth Rich is a fiction author. In It Could Have Been Murder, three friends start a murder adventure company called Diamond Teams, which assists groups or individuals in organising every facet of a murder, including choosing a target, all the details, and any contingencies—all without actually killing anyone—and then conducting a thorough debriefing with the client. Each customer must pass a rigorous screening procedure to guarantee Diamond Teams won't help someone kill a target. However, after 20 years, one client eludes them. He demands retribution after his project is cancelled. Diamond Teams needs to devise a strategy to deal with the former customer, but his approach is not what everyone had anticipated. The former client must be outthought and outplayed by Diamond Teams before he causes them irreparable harm.