Shortly after surviving Winnie-the-Pooh’s and Piglet’s killing spree, Christopher Robin flees the Hundred Acre Wood and returns to Ashdown, his childhood town, seeking help. The corpses of Maria and her friends are recovered from the woods, but Christopher is wrongly blamed for their deaths. The incident, dubbed the “Hundred Acre Massacre,” leads to a film adaptation that damages Christopher’s reputation. Few people believe his story, including his childhood friends Lexy, Finn, and Aaron, his parents Alan and Daphne, and his younger sister “Bunny.” Now an outcast, Christopher suffers nightmares about Pooh and seeks hypnotherapy from Mary Darling to deal with the trauma of his twin brother Billy’s kidnapping years ago.

In the Hundred Acre Wood, Pooh and Piglet hide with Tigger and Owl after their home is burned down. They slaughter three university students in a recreational vehicle, prompting Owl to suggest attacking Ashdown. Hunters led by Aaron ambush the creatures, killing Piglet as revenge. Pooh kills the hunters but Aaron survives and returns to Ashdown. Due to the town’s backlash, Christopher loses his job and undergoes further hypnotherapy with Mary. When Aaron arrives at the hospital, Christopher confirms that Pooh attacked him. He also confronts hospital janitor Cavendish, who reveals that he kidnapped Billy for Dr. Arthur Gallup’s experiments, turning children into half-animal hybrids buried in the Hundred Acre Wood.

Christopher learns that Billy was resurrected as Pooh and warns the town about the imminent attack but faces ridicule. As night falls, Pooh, Tigger, and Owl rampage through Ashdown, killing several residents, including Finn, Alan, and Daphne. Pooh attacks Lexy, but she survives. The creatures then slaughter partygoers at a warehouse rave. Christopher arrives, fatally shoots Tigger, and learns that Bunny was kidnapped. He returns to the Hundred Acre Wood to fight Pooh, who subdues him. Christopher calls Pooh by his real name, causing Pooh to momentarily remember his childhood before accusing Christopher of abandoning them.

Lexy intervenes, stalling Pooh long enough for Christopher to kill him with an axe. CCTV footage of the killing spree exonerates Christopher, and Bunny is found unharmed. The police clear Christopher of any wrongdoing. Owl, having survived, recovers the bodies of Pooh, Tigger, and Piglet, vowing to find a way to revive them and seek revenge on Christopher.