Light pushed back from the keyboard and rubbed his eyes groggily. It was past 4 a.m. now, and they had been searching for a pattern to Kira's murders for hours. Articles, names, dates, times, and causes of death whizzed past them on the screens. Ryuuzaki, scrunched up in his regular position, stared wide-eyed and unblinkingly at the data streaming by. If Light hadn't known any better, he'd wonder if someone with such a vacant expression could possibly be absorbing anything at all. The only sign that Ryuuzaki wasn't sleeping with his eyes open was the hand that reached out and automatically plucked a sugar cube from the large ceramic bowl on the workstation every few minutes. Light's brain, slightly delirious from the surplus of information and lack of sleep, noted that the procession of sugar cubes from bowl to mouth was as regular as the hands of a clock. He blinked away the thought.

"I think that's good enough for today," he said, flexing his hands, which had been moving between keyboard and mouse all night.

"Giving up already, Light-kun?" said Ryuuzaki, not taking his eyes off the screens. Another sugar cube disappeared between his lips.

Light threw him a look. "Who said anything about giving up? I'm merely pointing out that it's late, and it would be better if we resumed this after we got some rest. A tired mind is more likely to miss something important."

Ryuuzaki turned his head owl-like and looked at Light blankly, as if the idea of sleep was foreign to him. Light sighed. If he'd known that he was volunteering to be chained to someone who was not only eccentric, but an insomniac as well, he might have given his actions more forethought. But no, this was the only way to prove that he wasn't Kira. He just had to remind himself of that.

"Ah, you'd like me to stop as well," said Ryuuzaki after staring a moment longer, as if he'd just realized this.

Light swore Ryuuzaki couldn't possibly be this slow, but he could never be sure about that, or about anything having to do with Ryuuzaki, actually. It was possible that Ryuuzaki was doing this merely to irritate him and, from his reaction, to tell him whether the likelihood of him being Kira went up or down some minute percentage. Then again, it was possible that Ryuuzaki was getting some secret kick out of pushing Light's buttons.

"Well, I'm not tired, but thank you for your concern," said Ryuuzaki, turning back to the monitors.

Or maybe he really was that slow when it came to other people. Light could feel the beginnings of a headache forming behind his eyes.

"Ryuuzaki, I meant that I'd like both of us to stop so that I can get some sleep," said Light, jingling the chain between them to punctuate his point that this was for him and he could care less whether Ryuuzaki was tired. While it pained him to admit defeat in anything, he knew there was no point in trying to keep up with an insomniac.

Ryuuzaki gave the chain connecting them a curious look with one finger stuck in his mouth, holding a sugar cube in place while he sucked on it. One second passed, then another as he worked on the cube, cheeks drawn in, looking very much like one of the stupider species of monkeys out there. Light suddenly felt like shaking him.

"If you'd like to get some sleep, I could ask someone to bring in a cot for you," said Ryuuzaki at last, reaching for another cube.

Exasperated, Light grabbed the sugar bowl off the workstation before Ryuuzaki could get another cube. Ryuuzaki's expression changed immediately, and if Light had any doubt that Ryuuzaki had been testing him earlier, it was dispelled now by the sharpness in Ryuuzaki's eyes.

Interesting, thought Light. Rarely did Ryuuzaki break from his carefully blank façade, but apparently his move had been unexpected enough to cause him to drop his guard, if only for a moment. This had potential.

"You know," said Light, holding the bowl carelessly in his hands, but keeping it away from Ryuuzaki, "you shouldn't eat so much sugar. It isn't good for you. You'll become diabetic. And it's no wonder you have energy still. All this sugar must keep you on a sugar high for hours."

Ryuuzaki narrowed his eyes. Light allowed himself a small smirk. This was fun. Ryuuzaki was looking at him now with the same concentrated look that he wore when he was considering different approaches to solving a problem, and the intensity and blatantness of that look make Light's skin tingle.

But then Ryuuzaki's eyes abruptly glazed over and he shrugged, apparently losing interest. He turned back to the monitors without a word.

Light watched him, slightly annoyed. He still had the bowl hostage, but it wasn't a game if Ryuuzaki refused to play. Unless Ryuuzaki's defense was to pretend that the sugar wasn't important to him, thus removing the advantage from Light. It would be the most logical and effective counter. Light knew, however, that the sugar did matter to him, or else Ryuuzaki wouldn't have revealed himself earlier. The question was how to use this to his advantage. Light was contemplating his next move when he saw Ryuuzaki fish among his baggy clothes and magically procure a wad of taffy.

Touché.

Light smiled. So the game was on, after all. A part of him was wary that this game would serve as additional fodder to Ryuuzaki's psychoanalysis, but a larger part of him wanted to show Ryuuzaki just who he was dealing with.

The most logical counter for Light at this point would be to call Ryuuzaki's bluff and start eating the sugar cubes himself. The outcome would depend on how much candy Ryuuzaki was hiding in his clothes, and whether he was willing to settle for that amount, or if he wanted the sugar cubes in the bowl too. The more sugar cubes Light ate, the more pressure would fall on Ryuuzaki to give in before all the sugar in the bowl was gone.

Light was just about to pop a cube into his mouth when Ryuuzaki cut him off.

"There's no point in executing the hostages one by one," he said, without turning away from the screens, chewing noisily on the taffy all the while. "I have enough candy on me to last for three hours, at which point the others will start waking up and can bring me more."

Light frowned. "That's cheating," he said.

Ryuuzaki threw him bored a look. "I never said I would play fair. Besides," he said, turning back, "it's not cheating. It's utilizing available resources."

Light rolled his eyes.

"Why do you care so much about the sugar anyways?" said Light, picking up a cube and crumbling it idly. He liked the way the shape caved under the pressure of his fingers.

"Because I'll die if I don't get enough," said Ryuuzaki, still sucking on the taffy.

Light stopped.

"You'll die?"

"Mmhmmm," replied Ryuuzaki absently, picking at a piece of taffy stuck between his teeth. He pulled his finger out, examined the tiny lump of taffy on the end, and stuck it back in his mouth, sucking happily.

"I'm chronically and acutely hypoglycemic," he said, pulling his finger out with a light popping sound.

Light wasn't sure what to say in response to this. The bowl suddenly seemed heavier in his hands.

"It's rare, but don't bother trying to find my real name through medical records, it won't work," continued Ryuuzaki, as if they were chatting about something mundane, like the weather.

Light put the bowl down. He was feeling more tired now. "You still think I'm Kira and that I'm trying to kill you?"

"The possibility isn't zero," said Ryuuzaki, showing no signs of noticing the change in Light.

"If that's the case," said Light, "should you be telling me about your condition, if I could use this information to kill you?"

"Doesn't matter," replied Ryuuzaki, still completely unconcerned. "If you were Kira, you wouldn't choose this method of killing me."

"How can you be so sure of that?"

"Well," said Ryuuzaki, pulling his eyes from the screens to contemplate the ceiling with one finger on his chin. "Well, if you were Kira, there are any number of ways you could have killed me directly by now. You could hit me over the head with a heavy object while I'm not looking, electrocute me in the shower, although you'd risk electrocuting yourself through the chain. You could strangle me with the chain," he said, counting it off on his fingers, "poison my tea, stab me with my pastry knife, smother me in my sleep—"

"You don't sleep," muttered Light.

Ryuuzaki stopped listing ways and gave him an annoyed look, as if Light had said something stupid. "That isn't the point. The point is, if you were Kira, you would never kill me by depriving me of sugar. Kira wants to outwit me. He wants me to show me that he is superior, so his pride would never allow him to kill me through such a low blow. He won't go for a physical weakness."

Light nodded. He had also arrived at the same conclusion through his analysis of Kira's thought processes.

"Besides, you wouldn't kill me directly if you were Kira because then I would win and everyone would know that you're Kira," added Ryuuzaki.

Light was about to point out that Ryuuzaki would still be dead in such a scenario, despite being right, but he saw that Ryuuzaki had gone back to analyzing the data on the monitors, eyes wide and staring, hand absently moving from sugar bowl to mouth again. He sighed. Something told him that Ryuuzaki wouldn't care so much about being dead, so long as he was right.

And then Light realized that Ryuuzaki had won their game after all.

"Hey! You told me that just so I'll give you the sugar back. You're probably not even hypoglycemic!"

Ryuuzaki didn't bat an eyelash, but continued watching the screens and eating cubes from the bowl, which was now tucked safely in his lap.

Note: My first Death Note fanfic. Feedback welcome.