Atem had once thought he knew what solitude was.

After all, after five thousand years of being locked away in the Millennium Puzzle, it was safe to assume he could speak from experience. Though his memories of the time were hazy at best, he distinctly remembered the all-encompassing darkness that being a sealed soul involved, along with the pervasive loneliness and feelings of isolation.

Partner…

Was Yugi suffering the same fate as he once was? Was Yugi feeling trapped and alone? Even worse…would Yugi lose his memories as he himself had?

Or would he even be able to rescue Yugi? From the sound of what Rafael and the other servants of the Orichalcos had said, souls that were stolen by the seal were devoured…

Orichalcos.

Funny how a single word could draw up such mixed feelings.

Anger.

Hatred.

Self-loathing.

Shame.

Intoxication.

Atem shuddered as he thought of the last. Even now, hours after he had made the crucial mistake of playing the Orichalcos, he could still feel its black power whispering temptations to the darker side of his soul.

It had a seductive quality. It promised strength, assured glory…and it felt good. Basking under the Orichalcos-induced emotions had been a release of sorts, and Atem was steadily realising that it had begun to poison his mind not long after he had defeated Grerimo, when he took the Orichalcos stone after his opponent's defeat.

Atem had once thought he knew what solitude was.

But that was before he had lost Yugi.

Partner…

Atem clenched his fist in frustration, so hard that he could feel a little blood flow from fresh cuts on his hand. He felt the blood flow. Not the physical pain. He wished he could feel pain. It would give him something to concentration on.

Atem's chest heaved, and he punched the wall in frustration. He was glad the others were still in the compartment of the train. They couldn't see him like this.

Atem's guilt was two-fold. The first was obvious; he had sent away the one person who had saved him from an eternity of solitude. The person he had sworn to protect. The person whose life he had made a hundred times worse simply by being in it. Yugi wouldn't be in half the amount of danger if Atem wasn't a body-snatching wraith.

The second fold of his guilt was that a part of him – however small – wanted to play the Seal again.

He knew he shouldn't. He knew he couldn't. He knew it would only result in more distraught and despair.

What worried Atem was that he didn't care.

His partner was gone. His protégé, his friend, his confidant and someone he loved like a younger brother. It was his fault.

It couldn't be fixed. So why shouldn't he just give in to the temptations the Seal offered? Let it encompass his soul, let the darkness fill the void left by Yugi.

Only one thing was stopping him.

Yugi wouldn't want it. Yugi had sacrificed himself for Atem. His last words before the Seal took him…"I trust you, the other me…"

Trust.

That was one thing Atem didn't deserve.

How many times had Yugi been in serious danger because of him? Pegasus. The Shadow Game with Marik. And now this…

Atem punched the wall again, sliding to the floor.

Partner…

Atem had once thought he knew what rage was.

After all, he had experienced anger enough times, the look in his eyes chilling so many of his foes to the bone.

But, even combined, all the previous encounters with anger did not come close to the explosion of fury that appeared when Weevil had torn "Yugi's" soul card.

The strongest, most wilful anger, is not a fiery rage, but is icy determination. Any other emotions Atem could have had for Weevil – forgiveness, compassion, mercy –vanished under the ice-cold anger that appeared that moment.

It was only made worse when Weevil revealed the card had, in fact, simply been a common Bug card.

That was when Atem had, once again, given into his baser, easier emotions. Anger. Lust. Vengeance.

And it had felt so good.

The remnants of the Orichalcos within him had risen excitedly, whispering, its tendrils grabbing his heart and squeezing.

And Atem had given into it, for a time.

It stopped when Tea had grabbed his arm, pleading for him to stop. He obeyed.

But not because it was Tea. He had ignored Yugi, someone who mattered far more to him than Tea.

He stopped because he saw a cycle repeating. Someone grabbing his arm, telling him to stop. Him pushing that person away. Him losing himself and something important in the process.

He stopped because he saw Yugi's face and actions reflected in Tea's.

He breathed heavily.

It was over, for now.

Atem had once thought he knew what regret was.

After all, it was only fairly recently that he had lost his partner due to his own actions.

But it was nothing compared to what he felt as he saw said partner face him in a duel and play the Seal.

What have I done to you…?

Atem saw himself reflected. The anger, the desire to dominate and succeed, shining in Yugi's eyes…this must have been what he looked like not so long ago. He saw purity tarnished, innocence corrupted.

And it's entirely my fault…

He had played Divine Wind because the…the abomination standing before him was not his partner. Yugi wouldn't have wanted to live if his heart was so full of darkness.

Nevertheless, after activating the trap, he felt immense, bubbling regret rise up in him and he rushed towards Yugi, expecting hatred, anger, and bitterness.

What he saw was a forgiving smile.

Once again, Yugi had saved his soul.

Yugi's parting words had given a modicum of hope to Atem, who at last felt the whispering temptations of the Orichalcos in his heart wither and die.

He was free from its influence. He could think completely clearly again.

Yugi had saved him. Again.

Atem had once thought he knew what fear was.

After all, he had faced down someone with the ability to read his every thought, he had faced down the Egyptian Gods themselves.

But these experiences did not prepare him for the deafening silence that surrounded the room with Dartz and himself.

The battle was the culmination of the past few months. He had fought. He had won.

It came to this. Kaiba had fallen not long ago. His friends had all been knocked out.

It was just him, Dartz, and a chamber so large that the tiniest movement echoed loudly. It was the last quality that drove Atem to nearly surrendering. Dartz had broken him through psychological warfare, convincing him that he was nothing special, that he was only prolonging the inevitable, and that if he surrendered, he could be at peace – and help save the world in the process.

And be reunited with Yugi.

It was when the Seal began to close around him that the Puzzle lit up, activated by Atem's tears . It wasn't a strong, powerful glow that promised retribution or victory.

It was light. It was gentle. It surrounded Atem, reassuring him of what he was fighting for. It gave him determination and motivation.

Atem fought his fear.

Atem had once thought he knew what relief was.

After all, he had been in enough tight situations that warranted the emotion afterwards.

But it was nothing compared to the tumult of emotions that overtook him when Yugi's soul floated through the portal created by the Knights of Atlantis and landed in his hands.

"Partner…"

At long last, after countless battles, Yugi's soul re-entered his body. Atem met Yugi in their soul corridor, between their soul rooms.

"Partner…"

"The other me…"

There was nothing else that needed to be said. They simply looked at each other in relief, sorrow and tiredness.

Yugi smiled.

And it was then, finally, that Atem knew everything would work out. Because now that Yugi was back to support him, now that the stronger of the pair had returned, there was nothing they couldn't face.

Atem smiled.

A/N: I'm not really much of a Yu-Gi-Oh! fan any more, but when I was, the Orichalcos season was by far my favourite, probably because the YinYang concept has always appealed to me.

Not sure how this was, it's my first YGO fanfic. Chances are I won't be writing any others. Hope someone enjoyed it.