It's 1977 and the era of the serial killer begins. LAPD detectives chase multiple killers at the same time. They scour the Hollywood Hills for the Hillside Strangler while hunting the Skid Row Stabber downtown. And then another serial killer emerges...

The Hillside Strangler becomes a media sensation, but Detective Grogan believes it's two men killing together. Is a woman slain near the beach the work of another serial killer? Detective Lange pursues the Skid Row Stabber to a darkened movie theater.

Kenneth Bianchi is arrested in Washington State, suspected of being the Hillside Strangler. Is his cousin his murder partner? A young girl disappears in Huntington Beach, the victim of a serial killer who appears on the TV show The Dating Game.