Alex works in an arcade and has to work an extra late shift despite her 21st birthday. Her boss Tim watches the Disney classic Steamboat Willie on a movie projector and a Mickey Mouse mask talks to him. In a trance, he opens the closet and puts on the mask... Confused and frightened, Alex flees from the figure and meets her friends, who are throwing a surprise party for her birthday. When the party is in full swing, Tim/Mickey attacks the friends and kills some. The survivors realize that they can use Mickey's phobia of flickering light and knock him down in a strobe storm. But that's not the end...