Harry Potter was used to dreaming about his past. When he was young, he would wake up- sometimes in a cold sweat, sometimes with a shock, but often just with a slight feeling of unease in his stomach- and brush away a spider, bright green light and maybe the revving of a flying motorcycle's engine the only remnants of the dream he'd had.
There was a difference, Hermione had told him, between dreams where his brain was working through hard things, and dreams where he was seeing what Voldemort was thinking of. For a long time, it was the former. He had a lot for his brain to subconsciously work through, after all. He dreamt about the night his parents died. He dreamt about the sight of Voldemort's face on the back of Quirrel's head. He dreamt about the Basilisk's fang piercing his arm, Tom Riddle standing over his dying body. He dreamt about Trewlawny's prediction, and when Sirius asked him to come live with him, and when that was taken from him.
But then the new kind of dream started, when he saw Voldemort killing that old Muggle. And he didn't know what he had seen, he didn't know what it meant- he only knew that his scar hurt like hell, and it didn't leave him feeling too good. He wasn't just dreaming about his past now. He was dreaming about Voldemort's too.
He dreamt about Cedric's body. His arm being cut open, his own blood reviving the being who wasn't quite a man who had killed his parents. Priori Incantatem. The Death Eaters. Looming shadows made by gravestones and yew trees and Lord Voldemort's new body.
But those horrible dreams were being replaced with a door.
And he was supposed to shut it out.
Harry spent the year he was fifteen trying to get the darkest wizard of all time to stop invading his head. He dreamt he was a giant snake, he dreamt he was punishing his servants who had failed, he dreamt he was holding Sirius captive in the Department of Mysteries.
Oh yes, Harry Potter knew what it was like to dream about the past, the present, the things that never even happened, the things he didn't want to remember.
But he hadn't expected the dream he was having now.
"Don't kill him! DON'T KILL HIM!"
He'd never heard so much desperation in Malfoy's voice, and clearly neither had Crabbe or Goyle, who paused ever so briefly. Briefly enough for Harry to disarm them.
Spells flying, people hiding, and then the Fiendfyre, everywhere, roaring and burning. Broomsticks sitting in a heap, the rushing air not cool enough on their skin, and he's trying to find them, he can't let him die like this... Can't let them die like this.
A scream that pulls at him, and he flies faster than he ever has before, Searching through the crap a thousand Hogwarts students have thrown away, he catches sight of Malfoy, the fire glinting off his ridiculously blond hair like some sort of signal. He tries to take the offered hand, but they slip apart, and it's painful, he doesn't know if he can save him.
"IF WE DIE FOR THEM, I'LL KILL YOU, HARRY!" Ron yells, and he and Hermione pull Goyle up onto their broom, soaring away as soon as they can.
Malfoy's hands scramble, pulling at Harry's robes, gripping tight as he climbs, frantically, behind him. "The door, get to the door, the door!" He screams, his voice loud and hot in Harry's ear, and they're flying fast, and Harry can hardly breathe, struggling with the smoky air, Malfoy's arms crushing his lungs.
The Diadem.
Harry turns, dives, and Malfoy is yelling at him, confused and scared, as they almost fly straight into the flames. He catches the Horcrux, and finally heads for the door, and he can feel Malfoy's fingernails breaking skin as they dig into his chest, gripping him for dear life.
They're out of the room now, and they've crashed into the wall across the corridor, and they're on the floor. Malfoy is facedown beside him. Their legs are touching. The air is clean now, but Harry still can't breathe. He's got the diadem, and it's time to get up and get moving again...
And he wakes.