Camp Nightmoon, a summer camp, split up into two parts: a boys' camp and a girls' camp. The camp is surrounded by sloping hills and is next to a river.
When Billy arrives at camp, he notices that it's very strange. As soon as the campers arrive, they are almost attacked by wolf-like creatures. Mike, one of the campers, is bitten by a snake and is told that there is no nurse at the camp. Larry, Billy's bunk counselor, seriously injures one of the campers during a game of scratchball. Over time, many campers start disappearing.
One night, Billy is awoken by Larry unexpectedly. Larry guides Billy into the woods, and they find a group of boys and Uncle Al, the camp's leader.
Uncle Al provides the boys with tranquilizer rifles and says that they will need to hunt escaped campers. Billy refuses to hunt, and Uncle Al leaps at him. Billy fires his rifle at him. However, Uncle Al laughs and says that Billy passed. All of the missing campers and Billy's parents emerge from the woods. Uncle Al explains that he has been the subject of a government test. Billy's parents, two scientists, will be going on an important trip, and they want to take Billy with them. Because of his age, Billy needed to pass certain tests in order to gain clearance to go. Because of his bravery and logic, Billy passed all of the tests. Billy's parents will be venturing to a far away planet to investigate the creatures that live there. The planet is called Earth.
Camp Nightmoon is divided into two camps: a boys' camp and a girls' camp. In Welcome to Camp Nightmare, Billy doesn't see or mention many elements of the girls' camp, so the locations below are from the boys' camp.
- Mess hall
- Bunk 4
- The Forbidden Bunk
- Office (where campers drop off mail)
- Baseball diamond
- Pay phone area
The girls' camp likely also has a campfire area because Billy thinks he sees it at one point in the story.
Counselors and staff
While Camp Nightmoon features many counselors and staff members, only a few are named. The counselors wear green shirts and white shorts.
- Uncle Al (leader)
- Larry (counselor)
- Frank (counselor)