Harry awoke – well, he could suddenly see, anyway – in a stark-white, immaculately-cleaned version of Kings Cross station. He sat upright, looking around wildly. He was dead, he had to be. Was this hell? Waiting an eternity for a train to come? Of course that would be what hell was like.
"This isn't heaven or hell the way mortals understand it, my boy," came an familiar voice.
Harry whirled around, gawking unbecomingly at Dumbledore. The old wizard looked better than he had the day of his death, dressed in lilac robes with gold trim, his eyes twinkling at Harry behind half-moon spectacles. Seeing Dumbledore clothed reminded Harry that he was, among other things, not clothed.
"Sir, I-" Harry started in embarrassment. He tried to cover himself, and realized he was suddenly dressed. Jeans and a t-shirt, which felt strange, because they were cleaner and better-fitting than any of Dudley's hand-me-downs had ever been. He turned back to Dumbledore. "Sir, what's going on?"
Dumbledore nodded sagely, helping to lift Harry to his feet as he explained, "On the night Voldemort attacked, your mother performed ancient magic. Blood magic. It saved your life, but when Voldemort cast the fatal curse, a fragment of his spirit broke off. It settled into the nearest vessel possible."
Harry's stomach twisted.
"Walk with me, Harry."
The two strode side by side along the train tracks. They came upon a husk – a grotesque, bleeding form, vaguely human and certainly miserable, but it was wretched. Harry recoiled at the sight of it. Dumbledore smiled, terse, and said, "Behold, the great and terrible Lord Voldemort, destroyed by his own curse. This is a life without love, Harry."
"It's awful," said Harry.
Dumbledore nodded. "Indeed. But you shouldn't take pity on it, Harry – it's dead. Save your pity for the living, and above all else, those who live without love."
Harry and Dumbledore fell into a comfortable silence, gazing at the bruised and bleeding husk, the only blemish upon Kings Cross. "Sir," said Harry at length, "am I really dead, then? Is this all the afterlife is?"
Dumbledore chuckled, a sound Harry had sorely missed. "When you first arrived, you thought this was hell. If we are to use such terms to describe this place – this strange place between life and death – I believe the proper moniker would be purgatory. But in purgatory, you suffer for your sins and move towards heaven. Here..." Dumbledore's eyes shined, like moonlight on a lake. "Here, my boy, you have a choice."
"A choice, sir?" Harry said.
Another sage nod from Dumbledore. He gestured for Harry to follow, and they left the husk behind them.
As they made their way down the tracks, two steam engines came into view. One on either side of the platform, both gleaming white. They unnerved Harry – they were silent, with no conductor stirring within them, no passengers, and no cargo. It didn't seem right.
"You've done more than enough in the wizarding world's plight against Voldemort. He might not fall today, but your sacrifice has made his death possible. To move on to the afterlife, to join your family and fallen loved ones, it is entirely your right. And you would be noble for it," said Dumbledore. "But..."
Harry listened with bated breath.
"But, should something stir inside you, inspire you to return to the fight and be there for Voldemort's death, it is entirely your right. And you would be noble for it," the old headmaster continued. He fixed Harry with his keen gaze, somehow looking at him as both a pupil, and an equal. "So, Harry. What will you choose?"
Harry's eyes darted between the two trains, both identical except for the meaning they held to him. His heart yearned to see his parents, Sirius, even Snape. How he wished he could say something to Snape right now!
But then, his mind filled with images of his friends. Ron, Hermione, Ginny, Luna, Neville... Faces of first-years he didn't even know, faces of people who'd forsaken him on the Ministry's whim. Strangers, acquaintances, old friends, new friends, rivals, enemies. Everyone still out there on the Hogwarts grounds, fighting for their lives against and evil that could finally perish.
"The dead aren't going anywhere," Harry said at last.
Dumbledore smiled. "Good luck, Harry."
Harry grinned, his eyes suddenly stinging with emotion. I'll see you again someday, old friend.
And he made for the train.