Edward paused in the middle of another of his fanciful tales of alchemists and monsters, and gave Alfons a quizzical look. "You're not listening."

"Huh?" Alfons looked up from his papers. "Of course I'm listening."

"No, you weren't." Edward frowned down at him, arms crossed. "You don't believe me."

Not again. "Edward, I…" Alfons really couldn't come up with a polite way to say 'No, I don't believe you. Either you're lying, or you're crazy, and I don't know which prospect is more disturbing'. "They're very interesting stories," he temporized.

The answer did nothing to mollify Edward, who was never willing to just let things go. "They're not just stories," Edward insisted. "They're- look at me, Goddammit!"

"I'm trying to work," Alfons hunched over the desk, attempting to block out his roommate.

Edward slammed his prosthetic down on the table loudly. "Fuck the work! I can't live like this…" He dropped into the chair next to Alfons, head hanging. "Alfons, please. You think I'm crazy."

"I don't think you're crazy." Alfons cursed his communication abilities soundly. "Look, Edward, what was wrong with the way things were until now?" He gently touched Edward's right shoulder, the human one, and shook a little until Edward looked up. "I'm sorry I wasn't listening. Finish the story." He could never resist Edward when he looked so unhappy. Which, to be fair, was most of the time.

"You don't know what it's like," Edward's voice cracked, in one of his abrupt transitions from anger to depression. "I want…I can't…"

"I'm sure you'll manage to get home," Alfons tried. He wished he could believe in that other world, if only for Edward's sake.

"I…" Edward suddenly looked up at him, gold eyes completely focused. "I'll prove it to you. Will you let me prove it to you?"

Alfons recoiled slightly from the intensity of the stare. If there was proof…if it was true what Edward was saying…It would turn the world as he knew it completely upside down. How was he supposed to deal with that sort of thing?

Will you let me prove it to you. Edward was giving him a way out. He could continue living in ignorance, humoring his enigmatic roommate.

And yet, if the proof was there to be had, how could the scientist in him resist?

"Show me," he whispered.

Edward opened his mouth to say something, then closed it with a small half-smile.

Alfons waited in curiosity, his heart pounding.

Edward raised his right hand – and started unbuttoning his shirt? He was finding it difficult, only using his right hand, and his fingers shook with what might have been excitement.

The German squirmed slightly in his seat, the whole situation having abruptly become completely surreal. He must be dreaming, thought the part of his mind that hadn't died of joy at the prospect of Edward undressing in front of him. It was only in his fantasies that something approaching a normal conversation would randomly turn into-

Edward growled with frustration at the stubborn buttons, and Alfons wished he dared offer to help.

Finally the shirt was completely undone, and Edward was fumbling with the straps that held his prosthetic on.

"There," Edward said in satisfaction, grabbed Alfons' hand and pressed it right up against the left side of his chest. "Just please don't scream."

The blush that had been threatening all along now exploded full force. Scream? Why exactly would he protest against this? Alfons hardly dared breathe, his hand burning where it touched Edward's skin. He couldn't begin to guess what exactly his friend was trying to prove, but certain parts of him were enjoying the situation immensely.

"Well? Do you feel it?"

Alfons found it difficult to hear Edward's voice over the pounding in his ears. All his attention was focused desperately on keeping his fingers from twitching, that it took him a moment to register what Edward had said.

"Huh?"

Edward rolled his eyes theatrically. "Moron. The heartbeat."

Heartbeat? Alfons focused his attention on the palm of his hand. Where…. Icy cold suddenly gripped him. Frantically he pushed harder against Edward's chest, previous feeling completely forgotten, but it didn't change anything. The skin was still warm, he could feel slight movement when Edward breathed, but there was no heartbeat.

"Mother of God!" Alfons jerked his hand away as if he'd been burned, and nearly tripped over his own feet trying to get away. A demon! Edward must be a demon, he thought feverishly. How else could he be alive with no heartbeat?

"Alfons, calm down." Edward was advancing towards him.

With shame, Alfons finally understood his unnatural attraction to the man. Obviously Edward was some sort of succubus, sent to tempt him.

"Stay away from me!" Alfons grabbed a knife from the table and brandished it in warning.

He nearly panicked when the threat of a knife did nothing, and Edward continued to advance. For the first time in his life he wished he had a cross handy.

"I'm not going to hurt you." If Alfons had been listening, he would have heard the exaggerated patience in Edward's voice.

"Like hell you aren't! Heartless demon!" he shot back, still trying to keep his distance.

At that Edward paused, and momentary relief swept through Alfons.

"Demon?" the blond started snickering.

Could he make it to the door? Alfons wondered feverishly. He didn't dare yell, for fear of what the demon might do to him, but if only there was someone else around…maybe he could make a break for it, since Edward was busy laughing hysterically.

"Oh, for the love of-"

Before the German had taken two steps, Edward was on top of him. He had to be a demon, how else could Edward, who had only one hand, overpower him?

The knife skittered away, and Alfons brought both arms up to protect his face, whimpering in terror. All the horror stories the priest had ever told came rushing back.

"Stop panicking, dammit, you're supposed to be a scientist!"

The words had no meaning for Alfons. All he knew was that strong fingers clamped around his wrist, and then-

It took him several moments to realize that nothing terrible had happened yet. He was still lying on his back on the floor of his apartment, and Edward was still sitting on his stomach, an incredibly human expression of annoyance on his pretty features.

Edward's fingers were still tight on his wrist, and Alfons found the palm of his hand once again lying against Edward's chest.

Against his fingers, he could feel the unmistakable flutter of a heartbeat.

"See?" Edward said reassuringly, though he still looked like he was trying to fight off laughter. "I do have a heart. It's just on the wrong side."

"Wrong side?" Alfons tried to register the anomaly. His hand was now on the right side of Edward's chest, where he could feel the unmistakable evidence of a heart. Experimentally he touched the left side again. Nothing.

"I got flipped," Edward said gently. "On the way through. Right now, I'm like a mirror image of myself. See? Everything's on the opposite side."

"Everything…opposite?"

"Yeah. Just like with my heart. For example, in my world, the arm I lost was my right arm – and here I'm missing the left one. Same thing with my leg. I'm just reversed."

"So…" Alfons digested this slowly, "you're not a demon?"

He was rather insulted when that set Edward laughing again.

Only then did it occur to him that this was the first time he had seen Edward laugh like this, so hard he actually had tears at the corners of his eyes.

"You could have given me advance warning, you know," Alfons muttered, disgruntled. As embarrassment chased away initial panic, a new shock hit him. Edward was telling the truth, he realized. Despite everything, his roommate truly had come from a whole different universe.

But before that shock could dig its claws into his mind, Alfons woke up once again to the fact that he was lying on the floor, with a half-naked Edward sitting on his stomach. And if Edward wasn't a demon, that meant that the sinful obsession for the man was completely his own.

Of all the revelations this day, that one might possibly be the worst.