With Bonin behind bars, law enforcement hopes the nightmare is over—until another wave of brutal freeway murders shatters their illusion. This third killer is by far the most methodical of them all and, if not for a random police check, might have evaded police for years.

With Patrick Kearney behind bars, police realize another predator is on the loose—an in-depth investigation leads police to "The Freeway Killer" and his torture chamber on wheels. The murders suggest the work of more than one single killer, which escalates the horror, forcing authorities to finally acknowledge that multiple Freeway Killers are at work.

In the late 1960s and early 1970s, law enforcement agencies discovered a pattern of murdered hitchhikers and young men, their remains crudely disposed of in industrial-strength garbage bags. Their investigation led them to an unassuming aerospace engineer, who lived a double life as a sadistic killer.