"Cake, and grief counseling, will be available at the end of the test."
Light felt a whoosh of air behind him, and then the unnerving sensation of breath on the back of his neck.
"Something you wanted, Ryuuzaki?" he asked, after the silence stretched on for too long.
Out of the corner of his eye, he saw a long, spidery finger extend towards the computer screen.
"What is Light-kun doing in lieu of searching for Kira?"
Light grimaced, slightly. "It's four o'clock in the morning, Ryuuzaki—I haven't had any sleep. And I can't, with you forcing me to stay out of bed." He jingled the chain for emphasis. "But I can't focus enough to work, so—"
"Never mind that!" he said sharply. "Just tell me what this is."
Light glanced fully over at the finger with his blurred, aching eyes. ". . . It's called Portal. It's a video game."
"About?" he demanded.
"Er . . . it's all right there in the title, really. You get your way through these strangely designed test rooms using portals."
"And the reward . . ." L's voice trembled. "The reward is cake?"
"Uh . . ." His sleep-deprived brain couldn't come up with an immediate response to that, and by the time it had, he had already been shoved off his swivel chair and replaced by L.
"It's not real cake!" he said incredulously, standing up and looking over the detective's shoulder at the screen, where he was furiously shooting blue and orange portals onto the test chamber's walls. "It's cake for the character, not for you—you won't be able to eat it!"
But L wasn't listening. For the next half hour, Light could only watch as he went about solving the game's puzzles like a man possessed. As intelligent as he was, none of them posed any challenge for him, but he was shaky enough with the controls to die periodically—obviously, he hadn't played a video game before.
Still, nothing curbed his determination.
Until he saw it.
They had escaped the incinerator and were working their way through the facility towards GLaDOS when, on a wall at the top of a staircase, L came to a dead stop, and then slowly maneuvered Chell to the side so several lines of graffiti were in clear view.
"The cake . . ." L read, swallowing convulsively. ". . . is . . . a . . . lie."
Nothing good could come of this. Light just knew it.
"The cake," he repeated, slightly louder, "is a lie. The cake is a lie. The cake is a lie. THE CAKE IS A LIE? HOW COULD GLaDOS-SAN LIE TO ME ABOUT CAKE?"
L's hands slammed into the keyboard repeatedly, making the table shake and the computer beep loudly.
"GLaDOS-SAN! I SHALL DESTROY YOU FOR THIS BETRAYAL!"
Light backed away, very slowly, until the chain was pulled taut. He'd known L was strange, but this? This was just fucking bizarre. He was having an episode over a digital cake?
"Okay, the test is over now!" GLaDOS was saying, sounding desperate. "You win! Go back to the recovery annex for your cake."
"LIES!" L shrieked, reverting to English.
For the next fifteen minutes, L made his former determination look like nothing. GLaDOS didn't seem particularly concerned about his progress, if her continuous comments were anything to go by—
"Remember when the platform was sliding in to the fire pit and I said, 'Goodbye' and you were like, 'No way!' and then I was all, 'We pretended we were going to murder you'? That was great!"
—but L was getting closer and closer, and he only wanted one thing: bloody satisfaction.
Light sat, watching him play with the kind of morbid fascination that he might use to watch a car crash, and by the time L finally reached GLaDOS's lair, he was leaning forward a bit in anticipation (though continuously reminding himself that this was batshit insane at the same time).
"Well, you found me. Congratulations. Was it worth it? Because despite your violent behavior, the only thing you've managed to break so far is my heart."
"No," L hissed, shaking his head. "No. You broke my heart, GLaDOS. You broke my heart! No one lies to me—about cake!—with impunity!"
And the battle was on.
In the end, despite all the build up, it turned out to be very anti-climatic. Some rockets were involved—which L took extreme pleasure in arranging GlaDOS to be repeatedly hit with—but the majority of it involved throwing some of the robot's cores into an incinerator.
It was over in three minutes.
"No . . . cake . . ." L moaned, his hands falling to his sides as he watched the ending cutscene. "I—I can't believe . . . Light-kun . . . how could you let me play this game, knowing the cake was a lie? Does Kira wish to harm my morale?"
"I'm not Kira! And you were the one who wanted to play! You hijacked my game! And—and—" Light trailed off, blinking blearily at the screen. Was that . . . really what he thought it was?
"And," he began anew, "even then, I didn't let you play knowing the cake is the lie, as the cake is not a lie at all." He nodded at the screen, which L slowly turned to look at.
And promptly plastered himself against.
Light leaned back, rubbing his hands over his face, and decided that he was never, never playing Portal again.