Watch free: full movie Reefer Madness 1936

A high school principal warns parents about a 'new drug menace', then tells the story of clean-cut teenagers lured into a dealer's apartment, where one puff of marijuana leads to hit-and-runs, manic piano playing, madness and murder. It was made as a church-funded warning film in 1936, then sold on to exploitation distributors, and decades later it was rediscovered as unintentional comedy. Watched today it's a time capsule of 1930s moral panic, as interesting for what it gets wrong as for how seriously it takes itself. Short, strange and endlessly quoted, it later inspired a stage musical.

Watch it if you enjoy so-bad-it's-good classics, or you're curious how drug scares were sold in the 1930s.