Kevin Kilpatrick has served nine years of a life sentence for two vicious murders he pleaded guilty to but didn't commit fearful of the threat to his family posed by the real killers. Excop turned builder Sam Carew helped to put him away, so when Kevin's daughter appeals for his help in proving his innocence he can t really say no. He doesn t bargain on getting mixed up with one of the most ruthless and sadistic crime families in the country, however, nor with the spate of brutal killings in which the weapon of choice is a ball-peen hammer. Although Sam might be on the trail of the killer, his relationship with the superiors at Unsworth nick means that Sam will have to do some investigating of his own.