Tammy and Greg meet at a bonfire party in the Perth Roleystone hills and sneak away for some alone time to a long disused gravel pit. Once there they disturb two men burying a body. They attack and kill Greg and chase a near naked Tammy through the hills throughout the night. She is found by a farmer, dehydrated, suffering hypothermia and delirious. She tells Detective Inspector Sam Collins and Sergeant Jenny Markham of the Major Crime Squad what she witnessed and reports the murder of Greg. But his body is found in his burnt out car at the bottom of a cliff, and the death was reported as alcohol and speed related, which casts doubt on Tammy’s recollections.
Disbelieving the official crash report the detectives investigate to discover two serial killers who have been burying their victims at the gravel pit, for seventeen years. This is the biggest case of mass murder in the history of the West Australian Police Department.