Steve Boswell, tired of being constantly bothered by the first graders he coaches for soccer, wants to get a scary mask like the one that Carly Beth Caldwell got the previous year in hopes of scaring them for Halloween. Carly Beth eventually gives in and tells Steve and his best friend Chuck Greene that she had gotten the mask from the party store in town. Steve and Chuck sneak into the back of the store, where Steve finds a particularly creepy old man mask, but the kids are eventually caught by the shopkeeper. He threatens to call their parents, but Steve pleads to the shopkeeper to let him buy the mask. When the shopkeeper refuses, Steve runs off with the mask.
The next day, Steve finally gets to put on the mask. As soon as he does, the mask shrinks and melds with his skin. He becomes weak and frail. The spiders begin to crawl in the stringy hair and ears. Steve's voice becomes old and raspy. He tries to take the mask off, but is horrified to discover that the mask has become his face. Steve tries to call Carly Beth, but gets her father instead, who isn't happy that an old man is trying to call his daughter. Steve, weak to the point of needing a cane to walk, heads out of his house and finds the first graders. But instead of being scared, they're concerned about old man Steve and help him cross the street.
Steve eventually finds Carly Beth and Sabrina. At first Carly Beth is afraid of him, thinking he's a creepy old man trying to hurt her, but he soon reveals that he's Steve. He asks how to get the mask off, and Carly Beth tells him that her mask came off with the aid of a symbol of love. Steve tries the black and white cookies that his mom bought him, but his terrier Sparky ate them. He tries to hug Sparky, but that doesn't work either. Steve, Carly Beth and Sabrina return to the party store, hoping to find an answer. They find an old tuxedo, which they put in front of Steve. Suddenly, the mask detaches from Steve and attaches to the suit. The suit and mask dance away into the night. The kids are relieved until they run into Chuck who had put on an ugly purple mask he stole from the party store. Chuck tells them that he's having trouble removing the mask.
The events of the television adaptation are far different. The Haunted Mask that Carly Beth wore the previous Halloween rises from the ground that it was buried (despite it being attached to Noah Caldwell at the end of the original episode) and attaches itself to the shopkeeper. Instead of trying to scare first graders, Steve simply wants a scary mask like Carly Beth's. Steve enters the mask shop and steals the old man mask. He goes on a similar scaring spree like Carly Beth had last Halloween. Overtime his body begins to weaken and he is unable to take off the mask. Meanwhile, Carly Beth, Sabrina and Chuck try to find Steve after Carly Beth learns about the mask.
A frail Steve eventually runs into the Haunted Mask, who orders Steve to retrieve the plaster head of Carly Beth. Steve steals the head and smashes it. When the others arrive, Steve grabs Carly Beth. The Haunted Mask is about to latch itself onto her, when Steve saves Carly Beth just as midnight approaches, defeating the mask. Steve finally removes the mask as the shopkeeper tells Steve that he finally put the mask to rest. Later that night, Steve and Carly Beth throw their masks into the fireplace, destroying them. However, Carly Beth's mask comes back to life, only to be buried once more by Sparky.
The Old Man Mask is a disgusting, foul-smelling mask with yellow hair and green, wrinkled skin. The mask is crawling with realistic looking spiders while it grins an evil, single-toothed grin.
Unlike Carly Beth's mask, which made her more aggressive and powerful, Steve's mask makes his body feel old and weak, almost killing him as his body rapidly ages and deteriorates. Similar to the other mask, it becomes impossible to remove after being worn, with the only way of doing so is by being reunited with the old tuxedo or defeating the other haunted mask before midnight on Halloween.