In the tranquil town of Briarville, Missouri, a century ago, an evil force known as Trantor unleashed chaos by transforming innocent children into lifeless wooden puppets to feed its insatiable hunger. The courageous townsfolk, led by the brave Phineas Worrell, an ancestor of the infamous Ernest P. Worrell, managed to capture and imprison Trantor beneath an ancient oak tree, sealing his fate with a grave ritual. However, Trantor cursed the Worrell family, declaring that he would rise again on October 30th, the eve of Halloween, at the hands of a Worrell descendant. This treacherous curse foretold that each generation of Worrells would grow increasingly ignorant of their dark legacy.
Fast forward a hundred years later, a misfortunate yet lovable sanitation worker, Ernest P. Worrell, inadvertently stumbles upon an ancient book while helping friends Kenny Binder, Elizabeth, and Joey build a treehouse in the same cursed oak tree. Little do they know, this seemingly innocent act would awaken Trantor from his centuries-long imprisonment. As Ernest shares the haunting tale of Trantor with his friends, he accidentally unleashes the dark force that had been dormant for so long.
On the eve of Halloween, Joey encounters Trantor's lair during his walk home from the treehouse. The sinister troll grabs Joey's wrist, transforming him into a lifeless wooden doll, leaving Ernest frantic to rally the townsfolk for help. Unfortunately, his impassioned pleas fall on deaf ears as everyone is caught up in Halloween festivities, oblivious to the lurking danger. Driven by desperation, Ernest takes charge, determined to quell the threat posed by Trantor.
As the night unfolds, Trantor claims new victims, including a boy on a skateboard, intensifying Ernest and his friends’ quest to save their town from the vicious troll. While Kenny and Gregg wander through the streets, the devious Trantor uses Elizabeth's soothing voice to lure Kenny away before seizing Gregg as his fourth victim. In a twist of irony, despite growing concerns over the missing children, Mayor Murdock and Sheriff Binder continue their Halloween party at the school, thinking the children will eventually appear. Unbeknownst to them, Trantor crashes their gathering, capturing the mayor’s eldest son as his fifth wooden creation.
The cornered Ernest bravely confronts Trantor, leading to a dramatic showdown where Trantor transforms Rimshot, Ernest's devoted canine companion, into a wooden statue. Just when all seems lost, a whimsical twist of fate occurs as Ernest, wrestling with soft-serve ice cream, discovers that "mother's care" symbolizes milk—a vital weakness to exploit against the trolls. Inspired by this revelation, Kenny and his friends rally to form a robust battalion aimed at vanquishing Trantor's minions with milk-based attacks.
In the ensuing chaos at the treehouse, Trantor conjures an army of underground minions while Ernest valiantly tries to fend them off. As the townsfolk rush to the scene, they find themselves helpless against the overwhelming force of the trolls. With courage in their hearts, Kenny and his crew charge forward, wielding a milk-fueled attack to dismantle the troll army. As the battle intensifies, Trantor, infuriated by this turn of events, transforms Kenny into a lifeless wooden doll.
As Ernest devises a new strategy amidst the disarray, he comes to a crucial realization: if love can weaken the troll children, then it can surely affect Trantor himself. With a heart full of determination, he boldly confronts Trantor, displaying an array of intricate dance moves while showering him with affection. The spectators watch in astonishment as Ernest seals his fate with a gentle kiss on Trantor's snotty nose, igniting a supernatural chain reaction that leads to Trantor's exhilarating downfall.
With the malevolent Trantor defeated and the wooden dolls reclaimed, including those lost for centuries, the townspeople are joyously reunited with their loved ones. In a heartfelt moment following the climactic battle, Sheriff Binder acknowledges his previous doubts towards his son and Ernest, recognizing the enduring power of love and resilience in overcoming their trials.
