Daniel Challis, a doctor in a northern California hospital treats a scared old man, Harry Grimbridge screaming that "They are going to kill us" and clutching a Halloween mask from the Number One best seller, Silver Shamrock masks. But later Daniel is shocked when later that night, Harry is murdered in his hospital bed and the killer walks calmly to a car and blows himself up. His curiosity is more peaked when Harry's daughter, Ellie, arrives and tells Daniel that Harry was scared ever since he tried looking into the origins of the masks as no orders for them is being taken for the following year. Daniel and Ellie go to Santa Mira (home of Silver Shamrock) to uncover what happened and are horrified that the owner of the mask company, Conal Cochran, is planning to use the masks and some black magic as one great Halloween trick on the children that are wearing his masks on Halloween. As time draws near on Halloween night, Daniel must stop Cochran from sending the signal out to activate the masks and he can only do that if he can get out of Cochran's huge mask factory alive...
