Police respond to a call from a residential area of Dudley, where a woman reports that a house is being smashed up and a group are beating someone up outside it. When the forensic team from West Midlands Police arrive shortly afterwards, the attackers have fled. They find the body of a young man and a complex crime scene with evidence that a series of violent incidents have taken place over several hundred yards. Soon afterwards, a second man, brought to hospital from the crime scene, is declared dead. When strange puncture wounds are discovered on the bodies of both victims, a detailed forensic investigation is mounted to piece together a full picture of how and why the men were killed, what the murder weapon was, and who is responsible.