A suspicious bill, a coded plea, and the Graham Quartet are ready for action Out along the lonely stretches of Old Elm Road, the Graham Quartet feels a mystery brewing. When a string of strange happenings continues to point in the same direction, Elsa, Matt, Selena, and Tim are determined to get to the bottom of things. But are all of these oddities really connected? Or is the Quartet so eager for another mystery that they're making up trouble...