The children escaped HorrorLand, but soon find out that they have been tricked by betrayers like Byron, Jillian, and Jackson. They all suffer one by one. The first being Billy Deep, who turns into a shade (i.e. shadow person) when he tries to flee away. Later, Carly Beth follows the same fate from the shades. The children are forced to go to the theaters by Karloff Mennis. The chairs, which are living creatures, lock around them, and keep breathing in their ears. The movie shows the suffers and fears of Panic Park.
When the children are watching, the chairs copy the same actions as in the movie, including the roller coaster ride and the huge winds. Then, Britney and Molly remember that they had gone through a huge white building, and they had felt very cold and had suddenly reached HorrorLand, meeting Robby Schwartz. After talking with him for a time they reach Panic Park. The children are then lead to their rooms by Byron. Byron forces Matt Daniels to give him the key card by shaking him upside down, but Matt gives Byron his library card instead. Byron leaves the room, and, in his hurry, he forgets to lock the doors. Robby Schwartz asks Britney Crosby and Molly Molloy to remember how they were last at Panic Park and went to HorrorLand. They go to a building and meat Dr. Maniac. This is when Julie and Abby keep trembling, due to the Shake Shack and Robby getting turned invisible by Dr. Maniac's paint. They go to another building, The Hall of Mirrors. They meet their past villains in mirrors.mBritney is turned into a dummy by Slappy after he mocks about half of the other kids for what happened to them.
They escape with the help of Slappy, Captain Long Ben One-Leg, Dr. Crawler, Inspector Cranium, and other villains. They team up and defeat The Menace, by laughing, which shrinks Panic Park. They escape with the help of Jillian and Jackson and are all reunited with their parents... and all of a sudden, Billy and Carly Beth aren't shades anymore, Robby's not invisible, Michael Munroe is back to being one-faced, Abby and Julie have stopped their trembling, and Britney has her normal head again. After getting home, Lizzy finds she brought something home with her...a wooden dummy. The dummy (Slappy) opens his eyes. He tells Lizzy (who looked like a huge mess) that she looks good. Slappy then says this is the start of a new story that will really give her goosebumps...
...but what is it? You have to read When the Ghost Dog Howls to find out.
- Visiting hours to the Menace's study are on Tuesdays... until he was defeated.
- There is a time-warp quite similar to The Haunted School. In this book, Panic Park was stuck in 1974, but in The Haunted School, the class of '47 were stuck in Grayworld, where it's always 1947.