A senile old man is attacked in what appears to be an open-and-shut case of burglary. But Mike suspects the old man's obsession with his deceased son may have pushed his loved ones over the edge. Meanwhile, Greengrass organises the annual Aidensfield car rally and subsequently turns the rulebook upside down by agreeing to help one of the racers cheat.

The discovery of the skeleton of a baby in an attic reunites Bellamy with his childhood sweetheart as the Ashfordly team investigate the trials and tribulations of the fractured Lomax clan. The case leads Mike to a mental hospital, as he makes a horrifying discovery that sickens him to the core. Meanwhile, Greengrass and David begin selling wild rabbits as pets, leading them into trouble with a disgruntled pet shop owner.