Inspired by John Lilly’s psychedelic experiments and Robert Louis Stevenson’s cautionary classic The Strange Case of Dr. Jekyll and Mr. Hyde, Altered States depicts the quest of Dr. Edward Jessup to connect with the unadulterated, prehistoric root of human consciousness via psychotropic drugs and a tricked-out isolation tank. Offscreen, writer Paddy Chayefsky clashed with Ken Russell; onscreen, Jessup’s transformative trips put a strain on his marriage. The movie, Jessica Kiang asserted, “walks a tightrope between pretentious self-seriousness and outrageous flippancy. It is hard to conceive of a film more dazzlingly, dizzyingly divided against itself—or one more appropriately so—than Altered States.”