Charlie Harris is busy enjoying his new grandson when a mysterious man with a connection to Charlie's family starts visiting the library, bringing with him troubling questions about an unsolved murder . . .

Charlie may be a proud new grandfather, but he and Diesel still have work to do at Athena College and the small Mississippi town's public library. He's too busy to deal with true-crime writer Jack Pemberton, who wants Charlie as the subject of his latest book-and who won't take no for an answer.

A more appealing proposition for Charlie is spending time helping a kind, elderly man navigate the library's genealogical database. But he's shocked when he learns that the visitor's search is focused on a member of his own family: his late aunt's husband.

Charlie befriends the man and considers inviting him to stay in his home, but he's soon given reason to question that notion. Jack is certain that Charlie's new houseguest was involved in a shocking homicide that took place years ago in a small town near Athena. As this cold case heats up, Charlie and Diesel have to uncover a killer who may already be too close to home . . .