When Peter Petrelli came into the room, Hiro Nakamura nearly stabbed him.

He'd told Peter and Audrey very clearly that he was not to be bothered when he was meditating. Audrey had smiled grimly in that way she had, her cold cop-smile, but Peter had just rolled his eyes. That was the problem with Peter these days—he took everything either way too seriously, or not seriously enough. He hadn't thought, though, that Peter would be foolish enough to crash into the room like a racehorse out of a gate, startling Hiro with his sword so close to hand. But then that was Peter—never what you'd expect.

When he heard the door opening his body reacted immediately, the sword in his grip before his eyes even came open and slicing straight at Peter's head. He tried to check the blow when he realized who it was—wouldn't want to ruin that pretty-boy face, it's gotten us in more than a few doors—but of course it wasn't necessary. Peter grabbed the blade open-palmed, barely flinching as the edge sent blood spurting through his fingers, twisting the sword out of Hiro's grip and sending it clattering against the wall. Hiro jumped back a few steps, trying to throttle his kill-now adrenaline instincts back down.

"Ow," Peter said, glaring at him reproachfully. As he uncurled his bloody right hand, the wound knitted itself together like a blossom closing, turning to healthy skin in a matter of seconds. "Jeez, take my head off, why don't you?"

Hiro put an exasperated hand to his forehead, surprised as always at how cold it was after low-circulation meditating. "If you weren't so quick, I would have," he snapped. "I told you not to bother me when I was meditating."

"I understand now," Peter grumbled. "If you would have explained that you turn into a Samurai Killing Machine when awakened from your holy training trance, I probably would have been a little more careful. I thought you were just being antisocial and weird again."

"Peter, what do you need?" Hiro said, slicking his hair back into a tight no-fuss ponytail at the base of his head. "Please tell me you've got a good reason for interrupting me and almost getting yourself killed."

And there it was again—the Peter Petrelli switch. In an instant, Hiro saw him go from careless joking to dark intensity, an instant yin-yang switch that was as unnerving to him as Niki Sanders had ever been. He hadn't been like this, before the bomb—Hiro remembered when he'd been whole. "As a matter of fact, I do," he said, and he was deadly serious, no trace of the light banter left on his face. He pulled a chair out of from the coffee table and sat on it backwards, sliding a book across the tabletop.

Hiro picked the book up and turned it over, dubious. "Where'd you get this? You can't just walk into a bookstore—"

"Stole it," Peter said evenly. "It's called The Elegant Universe, Hiro. It's the answer to all our problems."

"Seems a little short for that," Hiro said dryly, but he looked at the book with a little more interest, flipping open the inside cover. "'String theory, many physicists believe, is the key to the unified field theory'—Peter, what the hell is this?"

"I know, it sounds like junk, but look." He snatched the book out of Hiro's hand and flipped open to a page near the end of the book. "Look at this chapter: More Dimensions Than Meet the Eye. Don't you get it? We've been doing this all wrong!"

Hiro shook his head, falling back into a chair. "Please, keep talking until you make sense."

"I've been reading through this all day," Peter explained. "This is what we've been looking for. We've been trying to fix the past, right? Going back and back and back, changing things, only nothing ever changes. The world just bends with us, swallows up our modifications and we always come back to the same present. We've been going crazy trying to figure out why."

"Crazy is definitely the word I would use," Hiro said sardonically.

"Well, this is why," Peter said, tossing the book down with a self-satisfied thump. "See, there isn't just one universe. There are—get this—twenty-six different dimensions. Twenty-six, and we've been running around in only one of them. Apparently, they're all sort of interconnected, and we won't get anywhere just changing one."

Hiro felt a very bad day fall onto him, bending his shoulders in with its weight. He put his head in his hands and tried to think of a way that this could be positive. "I should have known," he said, words muffled by his hands. "There were Star Trek books about this. A whole series. So, you're saying that we have to find a way to get to twenty-five other parallel dimensions, now?"

"Apparently that would be the thing to do," Peter agreed. A pause, while they both stared glumly at the holographic book cover, winking glibly up at them. "Any ideas?"

Hiro was saved a response—he did not, incidentally, have any ideas—by the appearance of the one person who could make his day better. Audrey Hanson stuck her blond head in the door, and he immediately perked like a watered flower—but she was not smiling, and suddenly it seemed unlikely that his day was going to turn better after all. "Code Delta," she said urgently.

"Honey," he explained patiently. "Peter and I don't actually understand any of your crazy FBI codes, remember?"

She thrust her chin forward. "I've explained them to you a million times, I don't know how you don't—"

"Be patient with us, Master," Peter deadpanned, "we are but your humble students."

"Would you shut up?" she snapped, and it became abruptly clear that there was, indeed, a serious problem. "Code Green! That means an enemy intrusion! Homeland Security is here. They found us."


AUTHOR'S NOTE: Sorry about all the tedious exposition, I just had to get it out of the way. String theory is B-O-R-I-N-G in theory, but kind of fun in practice, so we'll see if I can't get some action going soon :)