Disclaimer: It isn't mine. I wouldn't want it.
The Demise of Harry Potter
Somewhere between the fifth and sixth books, Voldemort, Snape, and Wormtail were sitting around, trying to come up with a way to rid themselves of Albus Dumbledore and Harry Potter.
"Poison," Snape suggested suddenly, though he had already said it many times.
"Too simple," Voldemort voiced his usual objection. "He'll see it coming."
"I could just slip something into his drink," Snape volunteered.
"Then they'll figure out who you're really working for."
"We could lure him away from the castle and then ambush him."
"He'll never leave the castle alone."
"Sure he will; he's an idiot."
"True, but, unfortunately, so are most of the Death Eaters."
"I could do it."
"Then they'd know you were a spy."
"Who would know?"
"Whoever figured out that you were both gone at the same time."
"All right, then you think of something!" Snape shot back. Both wizards turned their backs to each other and sulked.
"I know!" Wormtail piped up. "We could lure him into the Forbidden Forest and let the Centaurs shoot him!"
Voldemort and Snape both glared at the idiot.
"So what do you think we should do?" Snape asked.
"I don't know; you're the one who comes up with all the plans," Voldemort returned.
"Yes, we've all seen how well yours work, Voldemort," came a new voice.
All three wizards turned. The new arrival stood some ten feet away, cloaked and hooded in black.
Snape, the smartest of the three, jumped up and pointed his wand at the new arrival. "Who are you?"
"Expelliarmus!" the figure shouted, and, instantly, Snape's wand flew from his hand. The other two wizards' wands soon joined Snape's in the hands of the newcomer.
"Your name is Expelliarmus?" Voldemort asked, now thoroughly confused beyond the reasoning of his small brain, which, though not quite as small as Dumbledore's, was still exceptionally small.
"No," said the new arrival with a sigh. "My name is Polaris. Do you bozos want my help or not?"
Snape sat down. "Polaris, eh? Let me guess; you can transform into a bear."
"Nope; I'm not that predictable. In fact, I can't stand predictability, which is why I'm here. Everybody expects you to try to kill Dumbledore."
"Oh, really? Why is that?" Voldemort asked.
"Because it's the obvious thing to do," Polaris shrugged. "Kill Dumbledore, and no one will stand in the way of your world domination or whatever. I'm simply here to help you do it in an unpredictable way."
"You're here . . . to help us kill Dumbledore," Voldemort finally figured out.
"What do you get out of it?" Snape asked.
"I get to be rid of a pain in the neck, and have the satisfaction of knowing you'll soon dispatch of another."
"Hagrid?" Voldemort guessed.
"No," Snape shouted. "Harry Potter, you idiot!"
"Don't you dare call me an idiot, or I'll--"
"You'll what? Polaris has your wand!"
Polaris smiled. "Fortunately, Snape, Dumbledore is an idiot and still trusts you, even after the terribly obvious stunt you pulled, not really teaching Potter Occlumency."
Snape pointed at Voldemort. "It was his idea."
"Who's Potter Occlumency?" Wormtail asked.
Polaris looked at Snape. "I don't know how you can stand being around such idiots."
Snape shrugged. "If you think this is bad, you should see Hogwarts."
Polaris laughed. "So. Who wants to kill Dumbledore?"
"I will," Snape volunteered.
"But then--" Voldemort started to object.
"Oh, shut up," Polaris sighed wearily. "They will not know as long as he appears to be somewhere else. Isn't there some stupid potion that will make me look like him?"
Snape shrugged. "Sure. So how should I do it?"
"Just find some time when you're alone in the hall, take out your wand, and kill him," Polaris suggested.
"That's it?" Snape asked.
"Is there a problem?"
"No, I . . . I thought this was supposed to be unpredictable."
"Oh, hang unpredictability. Just kill the idiot. Pick an unpredictable time, and it'll still be unpredictable."
Snape nodded. "Good enough."
Polaris turned to go, but then, without warning, turned around and shouted, "Avada Kedrava!" Voldemort flew into the air. Wormtail quickly scampered away. Only Snape stood still.
Polaris held out Snape's wand. "Here. You'll want this."
Snape blinked. "Now, that was unpredictable. Why kill him?"
"He was getting on my nerves. Admit it, you wanted me to do it."
"But he'll just come back, anyway. He made a bunch of Horcruxes that you have to destroy to really kill him."
"What, these?" Polaris asked, holding out a picture. "I threw them into Mount Doom last week."
Snape grinned. "So are we still going to kill Dumbledore?"
"That depends. If he dies, the school will probably close down, and a certain wizard won't get to teach Defense Against the Dark Arts."
Snape stared. "You mean--"
"Yeah. He finally did something right."
"Well, then, I guess I can put up with him until he dies of natural causes."
"Thought so. And Potter?"
"Oh, I'll just give him a bunch of detentions. That's more fun. If you kill him, he's gone, and you can't do anything else to him. If he's alive, you can still torment him."
Polaris smiled, then turned into a bear and disappeared into the night. All was well and good, in the silent darkness.
Three days later, both Dumbledore and Potter were found dead. No one in their world of idiots could explain what had happened, but a certain wizard just looked up at the North Star and smiled.