It was 3 AM and Light couldn't sleep.

He allowed himself to toss and turn and feel sorry for himself for ten minutes before realizing, with no small amount of chagrin, that this was the exact time of night when he'd always found himself woken up by Ryuzaki tapping away on his keyboard right next to him. Apparently that was habit-forming over a matter of months, no matter how much he disliked it, and getting back his memories and generally returning to his old self didn't seem to have had any effect on that sort of thing.

Deciding that this, like many of his problems in life, was therefore entirely Ryuzaki's fault, Light headed downstairs to at least satisfy himself that he wasn't sleeping either.

A pair of wide black eyes were fixed on him the moment he was down the stairs. More surprisingly, they were peeking out above the top of the Death Note.

"Light-kun, I was thinking about waking you up... no, I was definitely going to do it. If you want coffee, Watari can bring some." Apparently satisfied with the long look he'd given Light, Ryuzaki turned his gaze back towards the pages of the notebook, staring into it so intensely that it looked as if he intended to divine all its secrets with sheer force of will.

"...I'm fine, Ryuzaki." It didn't seem like he was going to need caffeine to keep him awake, like it or not. Resisting the urge to rub sleep from his eyes—no way was he going to come off as more tired than the detective with his permanent dark circles, especially now that he'd been informed that he would have been awake at this hour even without his own idiotic reflexive habits—he sat himself on the couch opposite, eyes on Ryuzaki over the top of the notebook's cover.

"Aren't you going to ask me why I was going to wake you up?" Ryuzaki asked, the notebook dangling limply from one hand as he flipped the page with the other. Light could tell just by the sight of it that he was looking at the page with the torn corner again, no doubt wondering about what powers that little scrap of paper might hold... Not this time, L. You aren't getting any answers there.

"You'll tell me when you want to tell me," Light replied, a yawn slipping out before he could suppress it. Ryuzaki had already called Watari before Light even had the opportunity to object, and in a moment so brief that it still surprised him after months of this, the elderly man had entered the main room as quiet as a ghost, setting down a tray with two cups of black coffee, a bowl of sugar cubes, and a generous selection of creamers.

He was gone just as quickly, apparently aware without so much as a glance from his charge that his presence was not meant to be lingering.

"You're bothered by it too, aren't you?" Ryuzaki said, then, eyes flicking upwards.

Light looked him right in the eye when he took a sip of his coffee, not so much as a single granule of sugar in it. Delightfully, Ryuzaki actually furrowed his brows and looked away, as if he couldn't even bear to look at such a display.

"To prove this notebook really can kill—that much should be done before we can move forward with the investigation. Even catching whoever is using the second notebook right now... even with the presence of that Shinigami... this will be difficult if we don't verify it one-hundred percent. No, we need to verify it." Ryuzaki's voice was laced with distinct distaste, and even... discomfort? Concern? He was normally so carefully guarded, but something about his demeanor now had Light's attention as quick as a shark noticed blood in the water.

He already had an idea of where this conversation was going, but it would be suspicious if he clued in too quickly, when the Light Yagami who'd been working with the task force for the past few months had been so optimistic, so trusting, so forgiving. No, he had to play good for now.

"That would mean—writing someone's name down and seeing if they die. You're right, Ryuzaki, just the thought of that's giving me a bad feeling."

Ryuzaki shot Light a bland look. Light didn't even acknowledge him.

"—But there's bound to be a way to do it with minimal collateral damage," he continued, tone so earnest he felt like he should be patting himself on the back for a good performance. "What about arranging to have a death row prisoner use it? Someone who'd die within thirteen days anyway, so even with that rule..."

"That's a good idea, Light-kun," Ryuzaki said quietly, setting the notebook down on the table without taking his hands off of it. If this were a poker match, Ryuzaki's feet would undeniably be his tell—he was still as death from the ankles up, staring at the white blank pages with eyes that seemed a hair's breadth from glazing over, but his feet were twitching and fidgeting like they had a mind of their own.

Light took another long drink of his coffee, leaning back with an arm stretched over the back of the couch. He didn't really like it with no sugar like this, but his pride wasn't about to allow him to sweeten it now.

"That's not what's bothering you."

"There are two or more notebooks currently in our world. The chance that there are more than two is less than one percent, so let's say for now... there are two notebooks. One used by the first Kira and one used by the second Kira. When the first and second Kiras were in contact, Kira would have had access to both notebooks, but now—whoever the current Kira might be, they only have the one. The current Kira was aware of Higuchi and killed him, so the current Kira, even if they are neither the first or second Kira, knows of this notebook."

Light bit back a smile. Oh, this could be fun.

"...The current Kira probably killed Higuchi with the intention of stealing his notebook, and with that plan having failed, he'd be ready to do anything to get it. And he'd know that if the police had seized it, it would have to get tested one way or another... so it ending up out of your hands might be just the kind of opening he's waiting for."

Ryuzaki glanced at Light appraisingly. Suspiciously. Of course the thirteen day rule wouldn't fool him completely, but it'd be checkmate before he had the chance to prove it wrong... or with where this was going, he'd personally verify it.

"As per usual, Light-kun's deductive skills are remarkably sharp." Black eyes turned downwards, and Ryuzaki flipped to the rules at the front of the Death Note, seeming to skim them over. "So you most likely know what the solution would be, as well."

Light set down his cup, leaned forward slightly.

"It has to be tested without leaving this building, by someone who Kira couldn't possibly be controlling."

Ryuzaki took a handful of sugar cubes and dropped them into the second cup of coffee, stirring it with his pinky. Light nudged a spoon towards him, which went ignored. "Yes."

Showtime. Thoughtfulness, then—dawning realization. Shock. Concern. Light could have been an actor, in another life.

"You can't be serious, Ryuzaki."

Ryuzaki emptied six containers of creamer into his cup, leaning down to sip straight from the rim when it was too full to lift as a result. He held Light's gaze for a long moment as he downed the rest of the cup in one gulp. He didn't need to say a single word for Light to know he was right on the money. No, no, don't laugh. Not now. Not now.

"You must be insane," he said instead, the corner of his mouth twitching in what he hoped looked like disapproval.

"Not an unfair assessment," Ryuzaki mumbled, popping a sugar cube into his mouth. Light gave a practiced scoff of disbelief, running a hand through his still sleep-mussed hair.

"You're going to write in it yourself."