The cover illustration featured a ghostly dog growling at a nightfall with red eyes.
Cooper Holmes is an easy-to-scare twelve-year-old boy. He and his family have just moved into a new house. Cooper's family has moved from an urban dwelling in Boston to a house in the middle of a forest in rural Maine because of Cooper's mother's job. Cooper is something of a scaredy cat.
Cooper is so afraid of his new surroundings that he stays up all night thinking he sees strange, unexplained things through his window, like a snake (garden hose) and a horrible monster (bunny rabbit). He hears some scuffling below his bed and when he goes to investigate, someone tries to choke him to death. It is only his sixteen-year-old brother named Mickey who was wearing a wolf mask in order to frighten and choke Cooper. This then leads to the two boys fighting in Cooper's bedroom, only to be interrupted by their father, who tell them that fighting is inappropriate behavior for the first night in a new house. Mickey gets into more trouble and his father told him to either leave his little brother Cooper alone or he will start at his new school grounded.
Once Mickey leaves, Cooper hears two dogs barking outside his window. Cooper thinks it could be his older brother Mickey again. Still, Cooper believes it could be real dogs and this scares him. The next morning, Cooper investigates his backyard and the surrounding forest for any evidence of the two ghost dogs, but finds nothing. He decides to be brave and go into the forest.
While in the forest, he meets a strange red-haired girl named Margaret "Maggie" Ferguson. She knows Cooper's name and warns him that he and his family must move away, that their house is haunted. Cooper rushes away to go tell his parents that they have to move. On the way back to his house, two Labradors appear out of nowhere and chase Cooper all the way home. He tries to convince his family of the dog's existence, but they think he is lying. Cooper spends the rest of the day pouting in his bedroom, unpacking his snow dome collection. That night, Cooper hears barking from the living room. When he goes down to investigate, he sees a bag of potato chips torn open and scattered all over the floor. Mickey shows up and makes fun of Cooper. Cooper picks up and throws the gutted potato chip bag at Mickey.
The next morning, Cooper runs into Margaret and she apologizes and admits that the chips in the living room were part of Mickey's scheme to scare Cooper. Mickey had asked Margaret to tell Cooper that their house was haunted. But once she saw how scared Cooper was getting, she felt bad.
He asks her, if she believes him about the dogs. She says yes and they become friends. Then Mickey shows up in the forest, his clothing torn open and blood all over. He laughs when they freak out and mocks Cooper by saying "You always fall for fake blood."
Margaret and Cooper decide that they are going to come up with the perfect plan to get Mickey back. Margaret's family is leaving for Vermont so she stays with the Holmes for a few days. At midnight, the two prepare to deliver revenge on Mickey with their genius plan. Cooper and Margaret plan to tie a fake rat to a string and dangle it in Mickey's bed. Mickey fools them by hiding in the closet.
Cooper and Margaret see the two dogs running around the house and Cooper insists that the two go out and investigate. This leads to the two ghost dogs holding them captive outside their house, and then dragging them to a shack out in the forest. Margaret thinks they should go ahead and see whatever it is that the dogs want to show them. The two dogs shove the two children into the shack, where they fell down was a hole. Then the dogs start speaking to them. See, the ghost dogs were originally humans who were turned into dogs. They've been waiting for two humans to trick into going into the changing room, so they can take over their human form.
Margaret and Cooper turn into dogs. The dogs turn into Cooper and Margaret. As dogs, Cooper and Margaret communicate telepathically and try to find a way to tell Cooper's parents that they are not really dogs. Cooper tries telling them directly, but it comes out as, "Woof woof woof woof woof." The two dogs then try running around and barking some more, which only frustrates the Holmes. The ghost dogs then re-break into the Holmes’ house and Cooper tries to write a letter to his parents, but discovers that dogs can't write. The parents show up and ask the dogs "Didn't we just tell you to get out?!"
In a final act of desperation, Cooper hears the fake-Cooper telling his parents that he hates liver, when in fact actual Cooper loves liver. Realizing that this is his chance to convince them that he is the real Cooper, Cooper-Dog runs into the house and eats the liver from the plate.
Finally, Cooper and Margaret decide the only way to get the two humans back into the changing room is to drag them there. So they do, and the parents follow behind the two children getting dragged away by giant dogs, calmly noting that it should be interesting to see what the dogs want to show Margaret and Cooper.
Cooper-Dog and Margaret throw the fake Cooper and Margaret into the changing room. Afterwards, they jump in themselves. In a twist, they are transformed into chipmunks; two chipmunks had wandered into the changing room. Cooper's parents and Mickey come in and leave the shack with the impostors who are still in Cooper and Margret's bodies. The real Cooper and Margaret try to catch up, but the chipmunk-dogs cut them off before barking at them and disappearing into the woods. Cooper asks Margaret what they should do, and she suggest that they should hunt for acorns.
Cover Art Gallery
- Cooper and Mickey's father was mentioned by name in the book: Sam Holmes.
- The cover of the book is very similar to the Stephen King novel, Cujo.
- Early copies of this book came with a free "terrifying tattoo".
- Different early copies of the book (including the first printing) came with a fold-out poster.
- Stine has stated that this was one of his least favorite Goosebumps books, along with Go Eat Worms!.