Hazel Wallace returns from her training, as the new Detective Sergeant, and is put to work by Supt Mullett sorting out the mess left behind by DI Frost, while he is on extended compassionate leave. Before long she is called upon, when a man is found hanged in his home, and she suspects it was not suicide. Routine investigations show that a fresh set of fingerprints at the scene belong to an unidentified man who had been found drowned a year previously. Frost is summoned back by Supt Mullett to sort things out, and he connects a painting that appears to have been stolen from the hanged man with an art robbery & murder some years before.

Frost investigates two deaths: a homeless teenage girl, found beaten up and drowned in Denton's river; and that of an environmental health officer, after a dismembered arm is washed up on the shoreline. This leads to the investigation of a local meat processing factory.

A woman is found in a critical condition in a quiet village on the outskirts of Denton, a victim of an apparent hit-and-run incident. Her husband and daughter are distraught. Frost's investigation exposes the secret life of a corner of rural England.