In a future where a failed climate change experiment has killed all life except for the survivors who boarded the Snowpiercer (a train that travels around the globe), a new class system emerges.

William Friedkin's gritty police drama portrays two tough New York City cops trying to intercept a huge heroin shipment coming from France. An interesting contrast is established between 'Popeye' Doyle, a short-tempered alcoholic bigot who is nevertheless a hard-working and dedicated police officer, and his nemesis Alain Charnier, a suave and urbane gentleman who is nevertheless a criminal and one of the largest drug suppliers of pure heroin to North America. During the surveillance and eventual bust, Friedkin provides one of the most gripping and memorable car chase sequences ever filmed.