The few remaining residents of a Canadian sorority house are celebrating the onset of Christmas vacation, but a stalk'n'slash freak is on the loose and one by one the residents get suffocated, chopped etc. Will any of them survive? Director Bob Clark's tense, effective film is a precursor, in effect the template, to the 'stalk'n'slash' films, Friday 13th, Halloween et al, that would come a half decade later.