Warnings: Supernatural themes

Disclaimer: I don't own One Piece or any of its characters.

A/N: Two fanfictions posted in less than 24 hours. I'm on a roll! Here's my attempt at the supernatural genre. Please feel free to let me know what you think in a review.

Eternal Hell was quiet. It was almost unnerving, and this, coupled with the dim lighting, sent shivers skating up and down Ace's spine. Oh, how he longed to be outside, on the ocean where the sun lit up the sky and you could feel and smell the sea breeze as you watched the clouds float lazily in the sky. He had heard rumours about the higher levels in Impel Down, and it was almost laughable how the prisoners who were deemed the most dangerous suffered no specific torture. No blade-sharp trees, wild animals, fire or ice. Instead, you were left alone, by yourself, where it was quiet and dark. Solitary confinement.

Perhaps that was the worst torture method of all.

Ace wondered how quickly the time would pass. Having been sentenced to death, he had little interest in facing his impending execution, but the idea of spending the rest of his life here in Eternal Hell was almost worse. Maybe that was because he was trapped, alone, with nothing but his own thoughts... His own thoughts as he lamented his decisions. Blackbeard's heinous, victorious laugh echoed in in the confines of his mind and he shook his head, eyes closed, in a futile attempt to make it stop.

Was he already suffering insanity? He hadn't even been imprisoned for long, had he? Unless time really was speeding by unnaturally and the silence, boredom and thoughts had finally driven him to madness.

When Ace made a move to open his eyes, he was alarmed to find it even more of a struggle than usual. A cold, clammy feeling overwhelmed him. Moments of physical weakness were not uncommon in Impel Down, but something felt ominously different. Ace wrenched his eyes open and had he not been chained to the wall of the holding cell, he may have collapsed to the floor in shock as he took in the startling sight in front of him.

He was staring at himself. Himself was staring back at him.

It was a perfect mirror image of himself, with its arms and legs in the same position that his were, although it was not held by chains. It stared at him soundlessly.

It? What was going on? Perhaps he was dozing.

Ace closed his eyes and waited for a few seconds to pass before he opened them again. He watched as the thing in front of him opened its eyes.

It felt as if he had thrown himself into the ocean; his entire body felt as if it had been drained of all its energy and he was sure that only the chains were keeping him in a semi-upright position.

A memory flittered in his mind briefly before it vanished like smoke in the wind.

Ace opened his mouth to speak, and it did the same.

"What are you?"

It mouthed the words back at him.

The memory suddenly came flooding back. Some time ago, he had been out and had somehow struck up a conversation with an enthusiastic older man who had seemed eager to inform Ace of all the important tales that he had heard. After Ace had patiently listened to the first few while eating his meal, his narcolepsy had struck and when he woke up, the man had left. Now, the names of mythological creatures were beginning to come back to him, and Ace searched his memory for the right one.

Lamia. Gorgon. Minotaur. Orc.

Then he remembered, and the temperature appeared to drop several degrees as a chill flew through his normally warm body. He was beginning to feel even weaker, something that he never thought possible.

Doppelganger.

"It's your double," he had explained. "If it's around, you might feel weak, drained of energy. Most Doppelganger's are mischievous and malicious. It's a bad omen. If you see your own Doppelganger, then you're going to suffer bad luck."

"How bad?" Ace had humoured him by asking.

"It's an omen of impending death."

He had shrugged the folklore off. After all, he'd already seen stranger things in the Grand Line.

But now, as he stared his Doppelganger in the eyes, he felt panic rising up inside him.

"I don't suppose you could be mischievous by letting me out of these chains?" Ace quirked.

It stared back at him impassively.

"Yeah, didn't think so. It was worth a shot though."

When Ace blinked, the Doppelganger was gone.

In the remaining time that Ace spent in the cell, he didn't see his Doppelganger again. When he was informed that his little brother had broken into the prison to save him, all thoughts of the myth left him, and instead he spent his remaining time in the prison cursing his recklessness which had resulted in all this in the first place. He desperately wished that Luffy would make it out of this alive.

When Ace was hauled to his feet, still in chains, and told that the time for his execution had arrived, his thoughts were only of his brother. Ignoring the jabs of the guards who escorted him towards Marineford, he turned his head in disgust and shame, only to feel a familiar sense of fear return at full force. His heart began to hammer against his ribcage.

In his peripheral vision he could see the Doppelganger.

Previously obediently walking alongside the guards, he suddenly threw himself to the side. In their surprise, the guards didn't appear to have seen it. Ace felt cold as he passed straight through the apparition. It faded before his very eyes.

"Stop struggling! You can't avoid this, pirate." The word was spat as if it were a dirty word but for once, Ace ignored the obvious jab and instead thought about the myth. He had already been prepared to die before the Doppelganger had revealed itself to him. Was it merely mocking him? Reminding him of what was to come? Or had it arrived to seal the deal? Maybe once you laid eyes upon your Doppelganger, you had signed your death warrant and there was to be no escape.

Ace went quietly.

When the chains were off, Ace felt a familiar feeling of power surge through him. His flames burned brighter and hotter than ever. He thanked whatever deities were listening for his amazing little brother and his wonderful crew and captain, and prayed that everyone could make it out of here alive. Himself included. Because things were beginning to look up for him and he wondered where the Doppelganger was. Maybe it had been watching him his entire life and had selected the time to reveal itself to him because of its mischievous and malevolent nature; to mock him and torture him for whatever little time he had left. But maybe the joke was really on it, and Ace was going to be one of the few people who escaped his fate.

The battle raged on.

When the magma fist pierced his stomach, Ace knew that he had lost. And for a moment, he thought that he could see the faint outline of his Doppelganger, staring at him. But this time, it was not imitating him perfectly, as it had been each of the other times that he had seen it. This time, the corners of its mouth were tugged upwards in an evil smile.