“What’s the matter?” asks Carly Beth, panicking, her voice muffled behind a rack of mangled fangs.

“There’s no bottom to this mask,” Sabrina gasps. “There’s no place I can reach my hand in.” And the recurring nightmares of 100,000 preteens are born.  

With what is perhaps the most casually unnerving introduction to a TV special ever conceived, Goosebumps’ “The Haunted Mask” plants its infected roots deep within the first few minutes. The camera first pans across a line of masks — hellish ghouls with bloated flesh and contorted faces — before landing on the most hideous creature of all. But this face is alive. A pale, sickly looking man with a slight hunchback introduces himself as R.L. Stine just before he offers us one cruelly understated warning: “Viewers beware, you’re in for a scare.”

“The Haunted Mask” owes much of its impact to Stine’s simple and deeply psychological premise. A young girl named Carly Beth (played here by a bizarrely talented child actress named Kathryn Long) is sick of constantly being the butt of her friends’ cruel Halloween spooks. She wants more than anything to be frightening. After she acquires a particularly disturbing mask from a mysterious novelty shop, Carly Beth sets off on a sadistic orgy of hell-raising high-jinx. But it isn’t long before the mask begins to change Carly Beth, and the show’s prepubescent viewership is suddenly confronted with a complicated existential morality play about the price we pay when we choose to abandon our identity.

In short, the show starts with two precocious girls trick-or-treating on a misty Halloween night and ends with a satanic goblin-girl burying a realistic bust of her former (unmasked) self in a graveyard and shouting “I’m supposed to be me, but I’m not!” at trembling throngs of toddlers.

“The Haunted Mask” catches you off guard with its calculated subtlety — it relies less on cheap scares and more on a steady-building dread that suffocates like Carly Beth’s cursed mask. Figures are soft-focused and painterly, lit by moonbeams. The script is crammed with believable adolescent interaction and a melange of disturbing images (“These pumpkins are so rotten,” Carly Beth remarks casually during an early-on graveyard stroll). 

The result is a surreal horror soap opera more unrelenting than “Twin Peaks,” a lost relic of ’90s children’s horror and a genuinely frightening cerebral drama. 

Perhaps most unsettling, however, is the inexplicable secret harbored in the film’s opening credits. A decade later, screenwriter Jose Rivera would go on to write the Oscar-nominated script to the Che Guevara road trip movie “The Motorcycle Diaries.” What madness is this? How could such a weaver of nightmares be possessed to create life-affirming stories of friendship and adventure? What dark secrets lie beneath Che’s poetic cross-country travels? 

This, my beloved friends, is the secret of the mask.