If Edge of Sanity (1989) teaches us anything, it's never trust a lab monkey. When a messy lab monkey knocks chemicals onto the drug he is experimenting with, “Henry Jekyll,” played by Anthony Perkins, accidentally ingests it, and . . . here comes Hyde! Perkins becomes addicted to the drug and under its influence goes out into the night to slaughter prostitutes and indulge in sadomasochistic orgies. Along the way he masturbates streetwalkers like Carolyn Cortez with his cane. Then he cuts her throat, though not before letting her massive mams spill out from her torn top. Sarah Maur Thorp acts out weird topless fantasies as a naughty nun that makes Perkins forget all about his cane and jerk himself off! This film takes viewers to the edge of sanity and throws them over into the abyss of abnormal arousal.