The illustration shows a hooded ghost emerging from a tombstone in a graveyard near a beach.
The novel starts out with the Sadler siblings, Jerry and Terri, investigating a graveyard. Terri, the younger sister, loves making etchings of tombstones. While in the process of etching a tombstone, Jerry notices a pair of zombie hands shooting out of the ground. Terri and Jerry try to escape but it is too late as the zombie hands are clutched tight to Terri's ankles. It is all over, it is all a dream.
Jerry and Terri have been sent by their parents to spend a month on the beachfront with their distant cousins Brad and Agatha Sadler, an elderly but lovable eccentric couple. In the course of fooling around on the beachfront, the siblings meet a trio of young children flying bat-shaped kites. This sibling group consists of two boys, oldest Sam and toddler Nat and a young girl named Louisa, all three with the same last name as our heroes, Sadler and all three having the same freckle-pattern as the other Sadlers.
The Sadler Trio tells the Sadler Duo about how in the cave above the beach there lives a deadly ghost who comes out when the moon is full. After the group stumbles upon a skeletal dog that seems to affect the Sadler Trio a little too much, they explain that ghosts hate dogs because they can sense when they are around, so the dog was probably killed by the ghost from the cave. The Sadler Trio also tells the siblings that sometimes you can see a specter of light in the cave. Later, Brad attempts to convince the Sibling Duo that this glowing is merely the northern lights.
Of course, the lure of a ghost leads the duo to go investigate the cave. While inside, they find the source of the mystery light: it is actually being caused by the candles being lit by a creepy old man with long white hair and a thin gaunt body who lives in the cave. Jerry and Terri flee the cave and tell their new friends about the gruesome ghost they encountered. The Sibling Trio tells the Sibling Duo that they have a plan for stopping the gruesome ghost, from tormenting their beach town any longer.
The plan involves the Sibling Duo knocking over a bunch of rocks at the front of the entrance to the cave, thus keeping the ghost inside forever. The trio explains that the cave serves as a sanctuary and a ghost cannot escape from within, if it should be trapped inside. As the Sibling Duo goes to try to trap the old man inside the cave, they are accosted by the ghost and dragged within his lair. He sets them down in front of his desk and tells them the old man is not a ghost, he is their distant relative. It is revealed that the Sibling Trio are the ghosts. Even though Jerry and Terri had stumbled upon the graves of these three earlier in the book, somehow they have trouble believing this story. The old man tells them that he will let them go from the cave, if they promise to go check the far right side of the cemetery. It is his hope that they will return and aid him in trapping the three siblings in the cave by the same methods they had earlier suggested for trapping the old man.
When the sibling duo escapes and goes to check the cemetery, they see two freshly dug graves with their names on the tombstone. Finally the whole gaggle of children go to trap the old man ghost once and for all, yet the old man tricks the sibling trio into resting in the cave, which they are then bound to do. Then, finally, to prove that the children are already "ghosts" to the other children, the old man calls his trusty german shepherd. The dog goes crazy on the children revealing them to be ghosts to the surprise of our heroes.
The three children sadly admit they they died not only from the cold but from hunger and they never had a life at all. They then stare at the two human siblings and suddenly their ghostly skin peels off, revealing them to be ghosts. The horrible skeleton children are calling for the non-ghost cousins to stay in the cave with them and that they dug their graves for them. Jerry and Terri decline and the old man is trapped with the ghosts in the cave forever. The two human siblings go back to tell Brad and Agatha all about their adventure and the elderly couple is very relieved that the children are safe.
Suddenly the old man's dog conveniently bursts into the beach home and starts barking at the elderly couple. The couple are shocked that their secret is out. Agatha slams the door on the dog, as it continues barking outside. And Agatha asks to Brad, "Now what do we do with these two kids, Brad? What do we do with these kids?".
Cover Art Gallery
- The cover features the ghost of a cloaked figure rising up from a grave. But that ghost didn't appear in the story (although it could be possible that the ghost may have been either Brad or Agatha, since it appears to be an adult).
- There was an error at the scene when Harrison tells Jerry and Terri that their friends are ghosts. As soon as Harrison says that the cave is a sanctuary, Jerry tells the reader that "sanctuary" was the word Sam had used. It was an error because it was Louisa that said that.
- This story was adapted as a comic book in the Goosebumps Graphix book, Scary Summer and Slappy's Tales of Horror, drawn by Ted Naifeh.
- This television episode was adapted into Goosebumps Presents Book #13.
- Nat is completely omitted in the television episode.
- The dog is still in the house barking as the episode ends.
- This is one of the three books with episodes famed internet reviewer, Jontron, reviewed, with the other two being Don't Go To Sleep! and My Hairiest Adventure.