When the body of a young woman is found in wasteland, DCI Gene Hunt fears a serial killer he thought he'd sent down in the late '60s may still be at large. For Sam, the victim, a Beauvoir beauty rep like his own Aunt Heather, triggers vivid recollections of his childhood.

Utilising his knowledge of modern surveillance techniques, Sam is led to middle class suburbia where a local car dealer, Roger Twilling, is throwing private parties employing the poorly paid make-up girls to help out when the lights go down and the wife-swapping begins.

Sam and Annie go undercover as a young swinging couple to infiltrate the world of vol-au-vents, Blue Nun and lava lamps. Never one to miss out on the fun, Gene Hunt storms in uninvited with a female 'friend' posing as his other half.

As heroin hits the streets of Manchester for the first time, CID and DCI Hunt want culprits for the smuggling, the dealing and ensuing violence. As Sam tries to get to the source of the influx of this deadly drug, he finds himself intractably drawn to a beautiful young woman who was witness to a heroin-related shooting.