Harry finds out that that Sirius and Dumbledore are not really dead, but have instead decided not to let Voldemort take advantage of their productive capabilities any longer, and have gone and hidden in some mountains.

However, he then hears that Hogwarts, the one great symbol of everything that he holds dear, is under attack, and returns to put in one last effort to save it. In the process, he gets Horace Slughorn, magical creatures commodity dealer and spearhead of the free market movement, captured and tortured, which leads ALL the mountain-dwelling capitalists come out to save him, following which they promptly leave Voldemort to destroy himself out of sheer inefficiency.

Oh, and apart from the Mountain Camp, everything degenerates into crap. Because, you know, Voldemort’s gang didn’t ACTUALLY know how to use magic, they just made Dumbledore and Sirius do it for them.

Harry, Ron, Neville, Seamus, and Dean all play a song for all wizards in the world, in their band “Wizardklok” meanwhile, the death eaters try to attack the band. Dumbledore calls all his boys in the order of the phoenix to stop him. Dumbledore and Voldemort are in an epic flying scooter, when Bellatrix shoots Dumbledore off his scooter with a cross-bow. Voldemort proceeds to repeditally punch Dumbledores face to a hideous blood pulp. Then Harry kills Voldemort. Dumbledore lies on the ground motionless. You see the boys faces one last time then some omniciant guys tells everyone to wait and see while the rest of “Wizardklok” getting really drunk and drinking bleech while everyone around them keeps dying of accidental causes.

P.S. Dudley promptly died from a heart attack upon discovering Harry’s body.

After the final battle Agent Pendergast shows up and, upon pulling a complete mobile laboratory out of his suit, determines that Voldermort was not the culprit. After intense meditation, he divines that the actual villain of the series was some character you met on page 2 of book 1 and have never heard from since. He confronts said character, kills him, and the book will still somehow manage to end on a cliffhanger

Harry and Voldemort face off, about to fight …

FLASHBACK

Voldemort is a child, being told by an unidentified parent figure that he has a destiny to fulfill. It is revealed that Voldemort, due to the aftermath of the Final Battle, has been flitting through different time periods and is in fact his own father.

FLASHFORWARD

Harry is seen, 20 years after defeating Voldemort, in an isolated environment. He has to press a button every 108 minute to prevent the paradox of Voldemort being his own father from destroying the space-time continuim.

The shoots have grown to remarkable heights. The constipated junkie examines the long red needle protruding from the ghastly wound in his arm. Neck flaps and lollygaggers walk through the shadowed marble valleys and the old weary centipedes. The Boy looks through his glasses for the last time as he stumbles mindlessly through the dark to the halls of white flowers and florescent memories.

The End

Harry doges some Voldemort’s free balls (Who turns himself into a turtle)
and after a well timed jump Harry lands on a button that Voldemort falls into dying instantly. Then Harry unties- Ginny and gives Harry a kiss even though he just saved her life. Music and fade to black.

Harry and his friends gather together to evaluate the situation. Using each person’s strengths, they form a plan that would allow them the best chance to succeed, although their chances are still pretty slim. During the final run-through of the plan, Leeroy Jenkins, an eager young wizard, apparates into the middle of the group.

“Alright guys,” he says, “let’s do this.” The others stand there for a moment, puzzled, as he yells, “LEEROOOOOYYYY JEEEENNKIIIIINS!” He then dashes into the clearing of Death Eaters and begins his noble battle.

Dumbfounded, the rest of the group stands there, mouths agape, watching their plan unravel. Ron is the first to say anything, saying, “Oh my God, he just ran in.” The group panics and follows, shooting spells at the enemies at random and hoping for the best. Their frantic shouts echo a terrible fear and panic as they call out injuries and bark commands to each other. As the Death Eaters truly overcome them, their anxieties turn to rage toward Leeroy, the destroyer of their plans. “It’s not my fault!” he cried in response.

One by one, each of Harry’s friends and loved ones was killed at the hands of the Death Eaters. Finally, only Harry and Leeroy were alive on the battlefield, though their deaths drew closer. With his dying breath, Harry said, “Leeroy, you are just stupid as hell.” The last thing Harry heard before he died was Leeroy’s tender response: “At least I have chicken.

Voldemort is forced to unlearn his evil ways through aversion therapy.
One day while walking down the street he is brutally attacked by his
droog-eaters.A beaten and bloody Voldy is taken in by kindly Harry
who does not recognize him.One day while Voldy is singing in the bathtub
Harry realizes why his scar hurts and who is in the tub.
Harry then gives his pal Voldy a earwax bott’s bean which triggers Voldy to jump out the window.Harry is thrown in jail and while in the hospital
Voldy is offered a Ministry of magic job.

At the ministry of magic we see Voldy day dreaming about killing Muggles
in a rather gruesome way.

Voldy “I have been cured alright”

Pan out

As Harry and Voldemort square off in the intense battle, Harry narrowly avoids a killing spell and crawls beneath a rock for safety. Voldemort cackles and chides, “Ha Harry! You forget yourself! Look around, all your friends are dead!”

To Harry’s left, Hermione lies dead and bleeding. To Harry’s right, Hogwarts lie in ruins, everyone inside vanquished. And Cho’s pregnant, that’s why she was so moody. Voldemort cackles once more, and speaks to the reader:

“Ha! You didn’t think he’d win, did you? I mean he’s 18. Come on.”

*record scratch as Ron shows up at Harry’s side”

“Wow, bummer…this can’t be right.”
“Good call,” said Harry, “We can’t end it like this! Let’s do the mega-happy ending!”

*diddly do, diddly do…”

Voldemort falls in defeat as Harry triumphantly strikes down every death eater around with one, awesome move. Ginny runs down and announces she has a record deal. Neville realizes that true love can exist between two grown men, and no one died after all.

Otacon : Harry, be careful! Voldemort knows everything you’re doing!
Harry : Damn it! What do I do?!
Otacon : I got it! Swtich the controller ports!
Harry: What?

Just before the final battle, Hogwarts students are forced to choose sides. The Carrows and other Death Eaters who had been professorlitized were all booted by Potter under cover of his invisibility cloak. Despite Minerva McGonagall’s well-meaning intentions of sending the underage students to safety, Harry takes charge and points out that, should Voldemort win this confrontation, they won’t have any real hope in any case. (Also he notes that they won’t want to miss the epic battle scene.) Draco Malfoy and company do some swift calculation (okay, Malfoy does some calculation and the others do some grunting) after which Malfoy decides that Potter, insufferably self-righteous and angsty as he is, will probably win the day. At this point he stands upon Slytherin’s table (around which the chaotic debate quiets). Malfoy addresses his housemates:

“Lost in thought, my dear associates?,” he drawls coldly. “Then let me point your way with a notion. I have noticed a disturbing trend, in the past six and a bit years, which I feel obligated to point out. I think we can all agree that Potter and his fellows are generally the weaker in our yearly headbutting contests, correct?” Response: nods and murmurs of assent from Slytherins, glares from others. “Then why have we lost? Lost so consistently that in the past few years we have not even once won any significant contest over them? Why have the Dark Lord and his followers been thus far unable to kill Potter? We took his wand and his friends’, we locked them in our basement, we tortured them- but we didn’t manage to kill them! What is this one-sided providence? Fate is for Potter, it is so clear now! And I, for one, am tired of having the sweet, luscious fruit of victory and glory waved beneath my nose, then snatched away as soon as I feel secure in it! I am, in short, tired of being F**KED IN THE ARSE EVERY DAMN TIME POTTER DECIDES TO SET HIMSELF AGAINST ME! Potter clearly has more on his side than even he knows! I have seen the tight grasp with which the Dark Lord grips his followers! I have no intention of remaining under his thumb for the rest of my life, and if you know what is good for you- if you are not among those too weak to seek power- you must join forces with Potter (though it pains me greatly) and we must defeat He Who Must Not Be Named!” He glares around.

The assembled crowd stares in silence for a bit. “You sound…a little…home..home…uh, gay,” says Crabbe. “No homo.” replies Malfoy coolly, glancing casually in Hermione’s direction. Many of the slytherins join with Potter and company, some of them plotting betrayal. Malfoy turns to Potter, and makes eye contact, each sizing the other up. Malfoy asks, “Well then Potter. What time is it?”

“Game time, Malfoy. Game time.” With that, Potter gathers the army of Hogwarts about him like a cloak, and they set out to find the last Horcruxes together. Seamus feeds Blaise Zabini (one who decided not to join them) to Nagini, who promptly died of blood poisoning. With all of Hogwarts searching, the Diadem of Ravenclaw is easily found and it is placed, along with the other Horcruxes, into some well-controlled Fiendfyre conjured by Professor Slughorn. (epic battle goes here. Teachers do lots of stuff with their subjects, some folks bite the dust. Malfoy kills several Death Eaters, and Lucius Malfoy reluctantly throws down his mask and cloak just when he is about to be killed by his own son. Then, as he is about to join the Potter gang, he catches sight of a mirror and spends the rest of the battle smoothing his hair. The struggle lasts all night, but the Dark Lord is summarily beaten to a pulp when Neville has the bright idea of summoning some rocket launchers. The last words of the Dark Lord come in a tired rattle from his mangled, burning corpse: “Look at the first word of each Paragraph.”

Harry vists Dumbledore’s ghost to gain secret wisdom. He is told that he’s fated to marry his mother and kill his father, which is absolutely not what he wants to hear. On the road back to Hogwarts, Harry and some random wizard get in a road-rage battle, which Harry wins by thumping the other man on the head. Harry defeats Voldemort by answering a famous riddle and is made headmaster of Hogwarts. He marries a Beatrix and they have four children.

Thirty years later, a plague comes to Hogwarts and it is revealed that the man Harry killed was really James Potter and that Beatrix is actually Lily. The prophecy was proved true. Beatrix/Lily hangs herself and Harry uses an ultra-creepy blinding spell to pluck out his eyes. Ron takes over as Headmaster of Hogwarts.

Potter: “Do you expect me to talk, Voldemort?”

Voldemort: “No, Mr. Potter. I expect you to DIE!”

It is time, it is the highest time! Lo, I teach ye the overwizard!
What is the muggle to the wizard?
A laughing stock, a thing of shame!
And what shall the wizard be to the overwizard?
A laughing stock, a thing of shame!
Heed not those eaters of death, for I shall teach you… to eat of life!
That you may find life to be all the sweeter!
I teach ye the overwizard!
The overwizard shall be as a bolt of brilliant lightening from the dark cloud of humanity, and shall strike down all eaters of death and dark ones!

Thus spake Harry Potter.

The entire story is described in intense action combat sequences. The main hero is Draco Malfoy, who rebels against his evil Slytherin kin. Draco becomes a master of wielding two wands at once, a complex style that he uses to deadly effect as he combines acrobatic talents never-seen-before with twin spells.

Harry and Draco begin to work together, although Harry still judges against his kin, believing all slytherins to be evil. Hermione falls in love with the white-haired rebel, but Draco pushes her away repeatedly, unable to imagine what the future of half-Gryffindor, half-Slytherin children would be like.

Harry is defeated in a brutal battle with Voldemort, but survives. Draco doesn’t see this, however, and attempts to take steel-eyed vengeance.

Etc.

Jeff Somers style:

Harry grows up beyond his years, mumbling “Too old for this shit” several times a page. He is a gritty, badass sonofabitch with a mean curse-aiming arm. He spends his years fighting the same cyborg enemy (Voldemort). He eventually finds out that Dumbledore has been using him for his own agenda and Aveda Kedavras him right in the face. He walks out a free man.
But he’s still too old for this shit.

Brent Weeks style:

Harry dies three or four times in each book, brought back by an ancient magic. He has fallen desperately in love with Ginny, a childhood friend he saved from some rampaging Death Eaters, but is unable to do so when a female rival of his casts a marriage spell on him, rendering him unable to love anyone but the caster. He kills Voldemort anyway and goes and sulks for a long while. He becomes disillusioned with the world. And then he dies.
Again.
And he’s brought back. AGAIN.

Harry kills Voldemort in the middle of the book. The book actually ends when Harry gets ready for the Christmas ball, in the middle of the school year.