Ex-copper Sam 'Mad' Carew is bored so when a beautiful woman asks for his help he can't help but be intrigued. It seems Sam once helped to put away her father Kevin Kilpatrick for murder. Kilpatrick confessed to two violent murders but his daughter Alison adamantly refuses to believe in his guilt and uses every womanly wile to get Sam to investigate. He doesn't bargain on getting mixed up with one of the most ruthless and sadistic crime families in the country. As the body count racks up Sam realises he'll have to face up to the killer - the elusive and aptly named 'Hammerhead'.