It's time for Bessie and her friends to consider another cold case. This time, one of Andrew's work colleagues has come over to the island to observe the cold case unit at work. He's going to be starting his own unit soon, and he wants to learn all that he can about what makes the unit on the island so successful.

As it's the beginning of tourist season on the island, Bessie has trouble helping Andrew's friend find a place to stay. Eventually he ends up in a small hotel in Lonan, one that is owned by one of Bessie's friends. But there's a stranger staying at the hotel, a man who claims to be a long-lost relative of the owner. Bessie can't help but suspect a con.

Can the cold case unit solve another case and keep their perfect record intact? Can Bessie investigate her friend's "nephew" without upsetting that friend? And does Andy Caine really want to buy a mansion with twelve bedrooms when he's going to be living alone?