This story is based off the great video game "Ghost Master," so it will make a bit more sense if you've played that first. Still, even if you haven't you'll probably like it, as there's enough Calvin and the Eds. This right here is the true Halloween special.
The Darkling was once the most powerful ghost in the world and loved to tortured mortals. But after multiple exorcisms, he was soon left with only a little bit of power. He was luckily in an area with many ghosts. But the ghosts stayed out of the way of lowly mortals. Using his last bits of power, the Darkling took control of their minds, making them obey him. Somewhere in that area, he knew, there was a book with a ritual to bring back all of his powers, and the ritual could only be preformed by mortals. The ghosts' job was to get the kids at a nearby camp to preform the ritual to bring him back!

It was a rainy day at camp. Outside, three typical sheet ghosts, Boo, Wendell, and Quiver hovered around the camp building. Boo looked determined, Wendell looked bored and quite nerdy with his silly glasses on. Quivers was the fattest of them, and looked nervous as ever.

"Hurry up!" whined Quiver. "We gotta find some kids to preform the ritual!"

"Well, I was, like, eavesdropping, and I heard about these nerdy kids who like aliens and stuff," said Wendell. "Do aliens count as ghosts?"

Boo rolled his ghostly eyes. "Wendell, you're such a newby ghost! Aliens are NOT ghosts! We've gotta find some kid who would love to bring back an ancient demon ghost!"

Quivers thought of the Darkling and hid behind a wall. "The Darkling really scares me...do you think something bad's gonna happen?"

Boo kept flying, ignoring his friend. "Quiver, relax...for a change."

"What makes you think you're so great, Boo?" asked Wendell.

"'Cause I'm THE ghost!" replied Boo. "I've got the moaning, the chains...watch this..."

Boo flew around little Jimmy, who was out for a walk. "BOO!" With a screech, Jimmy ran away in terror.

"Hey!" said Wendell. "The Darkling said that we couldn't show ourselves to the mortals yet!"

"Is the Darkling here?" asked Boo. "I don't think so!"

A huge thug ghost with a machine gun appeared. His name was Knuckles. With a deep voice, he said, "Yo, boys, word's reached the Darkling that you guys are slacking off. He don't like that."

Another ghost, Blair Whisp, flew up. He was a small disembodied skull. "Yeah, we're all looking, too, and you're just scaring people!"

Not easily intimidated, Boo stuck by his point. "SO! I'm a ghost! I'm supposed to scare people!"

"Not if you scare off the guy we're supposed to find! Keep looking!"

Quiver was already flying away. "I knew this would happen! The Darkling will hate us!

Boo sighed and flew around Quiver, stopping him. "Eh, relax! He still hasn't come to power yet! He can't do a thing to us now! In fact, I think we should forget about him and go off and---" A strange jolt went through Boo's head. He fell in pain, landing with a cartoony SPLAT on the ground. "Weird...it was like something made me stop and..." Boo changed his voice to a drone-like one. "Must...serve...Darkling..."

Down below the Earth, the Darkling was listening to Boo. He was a huge, demon skeleton-like creature, obviously pure evil. He was the one who had zapped the odd ghost. "'Can't do a thing...' I can control your mind! Once they get the children to preform the ritual, I'll be back to torture mortals forever!"

Oblivious to the invisible ghosts in the room, Calvin and Hobbes were running around inside.

"What should we play?" asked Calvin.

"Well, it's raining out...I say we tell ghost stories!" said Hobbes.

"I've got a great one...'The Haunted House That Had a Curse With a Whole Lot of Blood and Gore!'"

Two ghosts sat next to them. One was Terroreyes, a floating brain, and the other was Archlight, a corpse.

"Hey, I like this kid!" said Terroreyes, who loved blood and gore.

"He could be the one who'll do the ritual!" mused Archlight.

"Ghosts are pretty scary," Hobbes was saying.

"Yeah, good thing they're fake," agreed Calvin.

"FAKE!" screamed Archlight, erupting in a green fire. "We can't use a nonbeliever! The Darkling says that at least one of the people doing the ritual has to truly believe!"

Suddenly, Hobbes noticed Archlight. "Hey...IS THAT A CORPSE AND A BRAIN!"

Archlight's fire immediately died down. "That thing can see us!"

"To the Darkling!"

The pair of ghosts flew out of the room and into the ground. Calvin looked around. "I didn't see anything."

"Well, I did! And there's more all around you!"

A few ghosts were standing behind Calvin, just as Hobbes had seen

"Uh-oh," they said.