Denton's last remaining quarry is vandalised. Frost finds a baby in his office and is delighed to discover it belongs to DS (previously WPC) Hazel Wallace. He gets Hazel to look into some burglary's that have been occuring just after removal jobs have been completed. At the quarry a second body is found, which causes them to call the police. The only witness to the murder is an autistic boy, who immediately becomes prime suspect. Frost finds out about some dodgy dealings in the past between the quarry owner and his former partner. The boy escapes through a window and the Officers on duty get a sever telling off. A woman comes in saying her 7-year-old son has been abducted by her husband. The quarry owner then turns up dead in a brook a small way from the quarry. The boy is found but he has rigged the Autistic boy is found and he has rigged Denton Quarry with explosives and threataning to blow the quarry and himself up. Frost manages to get the boy down but the explosives in the boy's bag still explode. Frost then goes and arrests the quarry owner's partner for the double murder and finds the other boy safe and sound in a removals depot. He arrests the missing boy's father for robbery.

DI Frost pursues a paedophile suspected of abducting a 10-year-old boy from a Denton Town football match. Initially, Frost is unsure whether the lad simply ran away or is genuinely the victim of a kidnapping, but when the boy is found dead and a man is found dead following a hit and run incident, the identity of the latter creates a frightening link to the missing child. When a second child turns up dead in a deserted quarry, Frost is in a desperate race against time to stop a third child being murdered. While Frost is contending with this a note arrives from a secret admirer and Mullet tries to push Frost into a promotion he doesn't want.