In the land between life and death four things happened simultaneously – Albus and Gellert returned with the final Horcrux, Jason woke, Tom arrived and Death appeared.
"Perfect, we're all here," Death said.
"Where exactly is here?" Tom inquired.
"Limbo," Jason informed him. When Tom noticed his lover's presence he ran to the man and quickly embraced him, "I'm so sorry," he mumbled tearfully.
"I know, love. I forgive you, there's no point in holding grudges beyond the grave."
Tom finally noticed the other figures, "Should I be worried that there's a teenaged Dumbledore here?"
"Not really, he's actually better than the old one."
"Umm...if you say so," a frown briefly marred his brow, "I recognize Jason, Dumbledore, and Grindelwald, also de-aged. But who are you Madame?" He turned to the gothic girl with her black clothes and hair, contrasting her white skin.
"May I ask what has brought you here? And, perhaps, why we are not in Heaven and Hell respectively," it was obvious where Tom felt he belonged and where Jason did.
"Ah, Tom such a gentleman. Albus and Gellert are here only temporarily, to help. You and Jason however have a choice, are you two truly lovers or enemies? Would you be able to spend the rest of eternity together?"
And the two were alone.
"Tom, I'm so sorry. I should have told you I was from the future and it was possible I could go back. It just felt like if I spoke about it that would make it happen."
"Jason, Jason, Jason," tears were gathering in Tom's eyes, "I'd almost forgotten how you were. None of this is your fault. You weren't the fool who killed your lover. There's absolutely nothing to blame yourself for."
"Tom, I love you so much. I've missed you these last 6 years," he was also sobbing at this point. Tom embraced him gently, "Does this mean we have decided we're lovers?"
"Would you be able to spend forever with me?"
"I would love to spend forever with you," Tom's voice lowered seductively, and he began to kiss Jason. They made love on the floor. Softly, lovingly, reassuring each other of their love and forgiveness.
When they returned the only person remaining was Death.
"I can see how you two resolved that," she smirked teasingly, causing Jason to blush, "Well, there are several things left to do. Firstly, Tom, you need to reattached your Horcruxes."
"Of course, how?"
"Like this," she snapped her fingers and the pieces of soul which had been gathered in the station entered Tom.
"It's that easy?"
"When you're dead many things are different; some easier, some harder. Now for the final decision. There are a few things I need to explain before you chose. You see, the two of you are soul mates. You can't live without the other-"
"But what about the prophecy?" Tom interrupted.
"Prophecies can be false and they can be misheard. I don't know what the issue was, that's Fate's domain. Maybe the seer was a fake, maybe it actually said 'Neither can live if the other dies' or maybe your trip through time change your destiny. No matter which, the fact that the two of you were born so far apart was dangerous since people with soul mates become sick, depressed or insane if their other half isn't alive. To make up for this mistake Jason was sent through time to be with you. Unfortunately a person must live and die in their time, so Harry was sent back."
"As interesting as this knowledge is, isn't it useless now that we're dead?"
"That brings me to the final point, the decision. You have two options and you must both agree on the one you pick. The first is to leave Limbo and die completely. Also, while I can't tell you what the afterlife is I can assure you that you will be together if you wish. The second option is that I will bring you back to life. You will arrive at the instant you first saw each other with memories intact. The side effect is that once A Master of Death, like Jason rejects Death they are immortal and become the eternal masters of the Hallows. Tom will also become immortal because of his Horcrux, but any other humans you know will eventually die. You'll have another chance, but since you won't die again this option is not 're-usable' you can take as long as you need to decide." Jason needed no time, he turned to his lover – "Option two?" Tom nodded.
Jason was back in a five year old body, wondering briefly if all this de-aging would become a constant in his life. Then the door before him opened to reveal the most important person in his universe.
"They'll do a good job," Albus said to his lover.
"Better than we did."
"Then again, we never got a second chance."
I will be writing a sequel A Second Chance. There is a poll on my profile about whether to have m-preg in the story, please vote.