When a homeless teenager is discovered beaten-up and drowned in Denton River, her parents tell Inspector Frost that they've neither seen nor heard from her since she suddenly left home shortly after the drug-related death of a close friend. Then, an environmental health officer's body is discovered washed-up on the shore a hundred miles away. Frost interviews the owner of a meat processing plant that the officer was investigating. Frost seriously questions their denials over the fate of the officer when he learns that one of the owners frequently pilots his own light plane and was flying on the day following the officer's disappearance. At the meat plant, Frost narrowly avoids sharing Barber's fate thanks to a new-found friend. Are both deaths related to illegal drugs?