Scientist Emil Hobbes is convinced that human rationality stifles his primal instincts. To free them, he develops a parasite capable of triggering the innermost sexual desires, experimenting with it on Annabelle Brown, his lover. However, the girl unwittingly transmits the parasite and turns the apartment complex where she lives into a hotbed of infection. The parasite spreads rapidly, mutating men and women into beings dominated by an insatiable and insane lust.
