The Curse of Camp Cold Lake

The Curse of Camp Cold Lake is the fifty-sixth book in the original Goosebumps book series. It was first published in 1997.

The cover illustration shows a female ghost emerging from the lake.

Blurb
Sink or...Sink

Camp is supposed to be fun, but Sarah hates Camp Cold Lake. The lake is gross and slimy. And she's having a little trouble with her bunkmates. They hate her. So Sarah comes up with a plan. She'll pretend to drown--then everyone will feel sorry for her. But things don't go exactly the way Sarah planned. Because down by the cold, dark lake someone is watching her. Stalking her. Someone with pale blue eyes. And a see-through body...

Plot
Sarah enrolls in Camp Cold Lake, which just happens to be near a lake. Unfortunately, she isn't accepted or treated well at all by the other girls except for one girl, Brianna. In order to get respect from the others, she attempts to stage a false drowning alarm until she can suddenly not resurface, which was not in the plan. She winds up in a ghost world and is taken care of by another ghost named Della River, until she is able to go back to reality. When she is brought back, she is still made fun of somewhat but eventually manages to get the respect of the other girls.

Unfortunately, she is still stalked by Della, whom she is convinced will drown her to be her undead best friend until she is cornered in the woods by Della, who reveals the existence of poisonous snakes in the woods and that was how she died, by snakebite. Sarah is almost about to be bitten when Brianna suddenly appears and knocks away Della, who vanishes into the grass. As Sarah is about to thank Brianna, she suddenly floats above and reveals herself to also be a ghost, killed by Della to be her friend. However, Brianna just didn't like her, but she likes Sarah, and wants her as a best friend. The only way that can happen is if Sarah dies, which Brianna plans to do with a snake as Sarah is powerless and cannot do anything to defend herself.

Trivia

 * The story of Della's demise is similar to that of horror movie villain, Jason Voorhees's demise from Friday the 13th.
 * There exists a version in which the book is literally half the book length, although still the same story, various parts were cut.