"Watari, I need you to make a harmless gun."
You're guarding Amane. The hidden bolthole in which the most dangerous Kira is being confined is known to no one; and, like all of L's hidden boltholes, it is plated in metal, a faraday cage that ensues absolute secrecy. There had been enough space to bring both kiras in, but L had insisted on keeping them apart. Truly, a sensible precaution—although you are fully capable of keeping them a mere room away from each other without either one ever knowing.
"A contradiction in terms, my dear boy," you reply amiably enough. Your workstation in the bolthole is, of course, fully equipped. You are already turning on the nearest lamp and disassembling a Japanese police-issue revolver.
L doesn't answer. You can hear him shifting, though—it's late in the evening, but L is ever-restless.
"The caterers are showing up?" you ask.
"Mm. Yes. Thank you. Watari…" L pauses. "What do you make of what happened to Amane? It's strange, isn't it?"
"Many things are strange."
"Inexplicable, then."
"Your job is to make it explicable," you merely say, unmoved.
L huffs. The sound crackles through the landline, as though he were almost standing beside you. There's a thud—the hollow thud of someone jostling the microphone—and then silence.
You close the connection on your end, too, and get to work.
Even a gun loaded with a blank can cause severe injuries, or death, at point-blank range. Hollywood knows it—and so do you; an unloaded gun isn't dangerous, you can remember saying to a mark, once. As her hand hovered uneasily above the cold metal. A lie, of course.
During your time in MI6, you came up with very many lies, very many ways to kill and torture, and you have shown each one to your protegé. L is, as much as you are, a machine—carefully programmed with every kind of cruelty, but there is one difference.
L's purpose.
From the moment you first met him, you knew. The child, small and unformed as children always are, still had an inexorability to him. Some describe drive as fire, but L's drive has always been cold, slow-moving as a glacier, and yet unstoppable for all its outward immobility. You had taken him with you already knowing that his purpose would be to protect the world, that even if you left him to his own devices, he would eventually stumble on that path.
After a lifetime of destroying, you think this is the legacy you'd like to leave behind: someone who can kill, but who knows not to. Someone who, instead, saves lives. This is why you always step back, no matter how many times L comes to you for guidance—because L has a vision you are incapable of. A vision of a future, of a justice unencumbered by necessary evils.
"A harmless gun," you say to yourself, amused; you peer inside the trigger, adjusting your spectacles against the bridge of your nose. "Just as you say, L. I'll do it."
.
.
.