Coffee is Murder — Carolyn Arnold

A cup a day won't kill you, but a few might.

Their first case as private investigators have Sean, Sara, and Jimmy neck-deep in coffee beans trying to find a killer. With their client certain that her mother was poisoned through her coffee of the month club, it has them setting out to Williamsburg, Virginia. But instead of approaching matters from the traditional standpoint, Sean and Sara brew a robust plot and stir Jimmy into the blend, all to get close to their top suspect and grind out the truth.

Going undercover at Tasty Beans, the coffee company, the three of them work to expose the culprit before anyone else dies.