Widower Harry Lancaster is in his late 60s, and he lives on his own in the retirement community of Lakeview Estates in Columbus, Ohio. He's a trained anthropologist who has also done work in roles of international diplomacy. Unfortunately, right now, his reach is limited. Harry is recuperating from hip replacement surgery. His daughter Cece and her family live in India so, even though they keep in close contact with him, they can't offer help from afar. Harry hires young Emma Stockton to be his daytime caregiver. Emma is a former critical care nurse who tends to be relatively easygoing, yet she is strict when she needs to be. This arrangement should work out well for both of them.

The residents of Lakeview Estates know one another, at least superficially and somewhat socially. They are all shocked when they learn that one of their neighbors, Sue Daniels, has suddenly died from poisoning. Sue had been known to go foraging. Had she accidentally poisoned herself? Independently, neither Harry nor Emma believe this verdict. It seems as though the local police officer, Detective Nate Bradford, has come to his conclusion far too soon. Harry and Emma both start thinking more about Sue and about the poison. Soon the two of them are discussing the possibilities of murder. Sue evidently had made some enemies in the neighborhood, and she may have even had ties to the CIA or FBI, as her husband had. Harry has government connections and can perhaps learn more. Emma can offer her viewpoint from a medical standpoint. Together, they also do some digging on the backgrounds of the other Lakeview residents. If Sue was poisoned, it must have been administered by one of the neighbors. Can Harry and Emma figure out what really happened? And will Detective Bradford even listen to them? He seems to be exasperated by their interest in the case.

Emma has a lot on her plate, away from Harry's house. She and her fiance Blake are planning their wedding. Or rather, their mothers are planning the big event. Emma is beginning to have her doubts about the whole idea. She needs to talk to Blake, but as a doctor, he's busier than ever. Helping Harry with impromptu detective work is Emma's thankful distraction from the incessant decisions about wedding themes and dresses and invitations and new apartments. Ugh.

A Field Guide to Murder is a cozy mystery with an engaging cast of characters, an interesting set of circumstances and a satisfying ending. Harry and Emma are realistic and likable characters, whether they are investigating independently or working together. Author Cullen even leaves the door open slightly for this unlikely duo to have more detecting adventures ahead of them. I sure hope that they do!