This compelling three-part true crime special takes a deep dive into one of the deadliest serial killer cases in California history. The unbelievable story begins with the 1984 vanishing of a San Francisco resident Paul Cosner. The search for Cosner leads investigators to unearth shocking discoveries at Leonard Lake's cabin, including buried human remains and Lake's recorded manifesto detailing his depraved crimes. As investigators unravel the dark truth, they launch an international manhunt for Lake's accomplice, Charles Ng, in hopes of securing justice for the victims' families.