Tom, an amoral Montreal drifter who supports himself by peddling dope and fleecing lonely woman, hooks up with Vicky, a straight-laced librarian, and initiates her, all too well, into his criminal ways.
When the residents of a luxury apartment complex outside Montreal are infiltrated by parasites and transformed into violent, sex-crazed maniacs, it's up to Dr. Roger St. Luc to contain the outbreak from spreading to the city.
