Disclaimer: I am not J.K. Rowling. I do not own Harry Potter.
Note: The following short one-shot takes place during the 'Goblet of Fire' year, on the morning of the 'first task'. It happens in a universe which started to diverge from canon (although Harry Potter has still been entered for the Triwizard Tournament) several months earlier, over the summer.
Warning! This piece is rated 'T' and is identified as 'tragedy'.
"An excellent idea, Peter." the short squat man with an uncanny resemblance to the muggle Antony Blazeworth sitting in the stands said.
"It… it just seemed so simple, my lord." his taller, thinner, companion who resembled the muggle Laurence Finings said, giving an impression of someone trying not to squirm too uncomfortably.
Neither wizard was actually who they resembled – their genuine counterparts were back at their hideout, trussed up, and the unwitting donors for some polyjuice potion.
"Please, Peter, no titles here today. And now, the grand finale." the shorter man said, obviously relishing what he was saying: "Harry Potter."
It was the date of the first task of the Triwizard Tournament, and Harry Potter stumbled out into the arena, to look at the Hungarian Horntail dragon which was the destiny awaiting him.
The shorter man who looked like Antony popped a couple of handfuls of popcorn into his mouth and munched, noisily. The crowd waited in hushed silence to see what 'The-Boy-Who-Lived' would do.
Five minutes later, it was all over, and the silence had mutated through one of various phases of expectancy, sympathy, and of anguished groans into a low murmur of horror.
"It was quite a good flame-freezing charm, was it not, Peter?" the man who looked like Antony said.
"Yes, err, Tom."
"One suspects he knew in advance that dragons were to be expected – someone with a big mouth on the Hogwarts staff probably blabbed. Wasn't the groundskeeper a friend of his?" the shorter wizard continued in an analytical tone.
"Hagrid? Yes." the taller wizard said, sounding slightly sick.
"Still, there's a lot more to a dragon than fire. Things like teeth and claws and wings. Oh. And a tail."
"Would you show some consideration here?" a wizard in the row behind demanded, clearly caught between states of being highly distraught and outraged. "He saved us all from You Know Who when he was but a mere babe. The magical community has lost a young but great hero today."
"If You Know Who showed up here, today, would the witches and wizards of Britain expect a fourteen year old boy to be the only one able to stop him for them? Not Albus Dumbledore? Not all the Ministry grandees and other great and good here today, sir?" the shorter man snapped back. "A fourteen year old boy who couldn't even stop what a dragon just did to him? Honestly, if that attitude had been prevalent a couple of decades ago, You Know Who would have won the Wizarding War." He turned to his taller companion. "Come along, Peter. The show's over today here, clearly."
It was forty-five minutes later, back in their secret lair, that the doses of the polyjuice potion which they had imbibed most recently, wore off, and the tall man and the short man resumed their respective true shapes as Peter Pettigrew and Tom Marvolo Riddle (the latter also known as 'Lord Voldemort'). Tom had been restored to corporeal form and full power a few months earlier, with the assistance of a ritual that used blood taken from the captured ex-auror, Alastor Moody.
"Definitely one of your better ideas, Wormtail." Lord Voldemort said. "Not trying to kill Potter immediately but instead infiltrating Barty into Hogwarts to enter Potter's name into the Triwizard Tournament. Why kill him directly myself, when one of my servants, acting on my orders, could enter him into a contest where he could be publically humiliated and utterly destroyed, damaging Albus Dumbledore's reputation too, in the process. And the entertainment value of it, on top of that…"
Peter Pettigrew shuddered, and hoped his master didn't ever realize he'd been trying to buy Harry Potter a stay of execution with his suggestion…
Author Notes:
In this universe Peter Pettigrew and Barty Crouch junior captured Alastor Moody, as in canon, but then used blood taken from him to fully resurrect Voldemort, almost a year ahead of the canon schedule.
Peter Pettigrew doesn't have a silver hand in this universe. I reason that the 'flesh of the servant' contributed to restore Voldemort was a sizeable piece of one of Barty Crouch junior's legs. (After all, if he's going to infiltrate Hogwarts disguised as Alastor Moody, to at least get Harry's name into the goblet, he may as well get some practice in with needing a wooden leg, as soon as possible.)
In this universe, having entered Harry into the Triwizard Tournament, Barty Crouch junior then did absolutely nothing to actively help him prepare for the first task. (Harry was entered into the tournament in this universe to destroy him in a highly public and humiliating fashion, so why would he help him?) He may have even take steps to ensure that 'Potter isn't cheating', to hinder him as much as possible. The flame-freezing charm Harry used may have been the best that Hermione could come up with.
Harry Potter is assumed by the end of this piece to be either dead or a long-term comatose St. Mungo's patient. (This piece *IS* identified as tragedy.) Presumably Albus Dumbledore doesn't survive the immediate fallout as either headmaster of Hogwarts or in any of his other political roles. If any good at all comes out of events, it might be that with suddenly not having anything else to do Albus throws all his time and effort into working out how Voldemort survived (if he hasn't already done so) and tracking down and eliminating the horcruxes (and then Voldemort).
This piece is a one-shot.
Update:
Peter and Voldemort abducted muggles to polyjuice themselves as because they wanted to reduce to the minimum any possible chance that other witches and wizards might 'recognise' them as who they were imitating and possibly grow suspicious that they weren't who they appeared to be. For whatever reason they considered this the most effective available form of disguise for attending the event (rather than say, false glasses, theatrical makeup, or transfiguration magic).