Disclaimer: I do not own YuGiOh, and I made no profit whatsoever in writing this fanfiction.

A/N: This is a gift-fic for Kimmie-chan (innominate). It's also the most stubborn fic I've ever written; it had four very different rough drafts before I came up with this idea. Unfortunately, this end result is a lot shorter than I wanted it to be, but hopefully you'll enjoy it anyway .

Laws of the Unknown

The Law of Conservation of Energy stated that energy could be not be destroyed. That was something that Anzu had learned in Chemistry, years and years ago.

Yugi Muto had been blessed with subtle, undeniable energy.

At sixty-eight years of age, Yugi had still seemed far from retirement. He had only spoken of his health problems to a few of his closest friends, and even they had been left to guess at how serious it was.

Even at his funeral, that energy he'd had remained. All through it, Anzu noticed Honda and Bakura and Jounouchi glancing quietly around as if expecting to see something. And even though she knew it was pointless since of them had seen anything strange since Atem had left…well, even so, she found herself looking around, too.

None of them commented on it when they gathered at the wake.

… … … … … … … … … … … … … … …

The dead supposedly knew everything. Atem said otherwise. He had been dead far too long to think that he was omniscient. There had been a time, once, but he knew better now.

That didn't mean he couldn't have premonitions. He had suspected Yugi was going to die soon when, inexplicably, he couldn't focus on anything but seeing the man again. The excitement had built and built and finally he'd been told that, yes, Yugi Muto had passed on at last.

Time passed magnificently quickly here; an hour here was about two years there. What he wouldn't have given to have that luxury in the Sennen Puzzle....

Except now that he was about to see his other again, it seemed everything had frozen.

Suddenly, when Atem was certain that a century must have passed in the living world, there he was. Golden and warm and very quietly mischievous, there was Yugi.

Atem had occasionally imagined what Yugi would look like as an old man. He had never been allowed to go and see for himself, and he was only slightly disappointed to find that he would never know. Yugi appeared, as he did, the age he felt most comfortable. Atem would eternally be eighteen years old; Yugi would forever more be twenty-three.

It was a little surprising to see Yugi as older than himself, and he told the man so. Afterwards he almost wished that those hadn't been his first words to his other, but Yugi only laughed and smiled and everything was fitting after all.

For a little while they walked, and things began to take shape around them to fit what they wished to be surrounded by. At the moment, they wanted trees and sand and faint sunlight. Yugi stopped then, a slight frown pulling at his lips.

When Atem only watched him, and Yugi had looked about himself as if expecting to find something where there was nothing, he asked, "Do they miss me?"

"Yes. Of course."

"It just seems like they should be here." Atem realized then that their surroundings resembled the park where Yugi and his friends had gathered so many times in so many years, before age had begun to pull them apart.

"They will be, much sooner than you think." Speaking of death this way would have seemed so morbid once. Now it was only filled with expectation and hope.

Yugi sat down and motioned Atem to do the same with a smile. "What have you done all these years?"

Deciding not to explain the time difference just yet, Atem settled next to Yugi and answered easily, "Resting."

"What will you do when you're done resting?"

A light came into the king's eyes which Yugi recognized all too well; the lust for the promise of a challenge. "I don't know yet. But I do know there are things I will need to do eventually."

"And me?"

"That is up to you." He smiled. "You could be reincarnated if you chose. I did not wish to; my one life was more than enough. Or you could stay here for as long as you needed. Or.... It's up to you."

There was silence. "I think I'll rest a while with you."

Atem smiled then, as Yugi leaned against him and he against Yugi. There was so much to talk about, so much they both had to ask and hear and do, but for now the peace of time sliding around them was enough.