Greig and Skase investigate a possible arson attack after a fire burns down a block of flats, killing a young family. Initially, the two seats of fire appear to suggest a deliberate attack, but when the father of the young children reveals they had been without power and were lighting fires to stay warm, Greig and Skase's attention is turned to the dodgy landlord, who they are determined to nail for involuntary manslaughter and neglect of duty.