You can read the whole fic on AO3.
Something stirs in the corner, a shade that barely takes form, and Shiro moves on him in a fluid lunge, muddled from sleep but wrapping the polymer of his mechanical fingers around the shadow’s throat on an instinct distilled in him through countless fights. He doesn’t crush the fragile breathing tube quivering under his grip but exerts just enough pressure to make it seem like he might. He doesn’t relish killing, but he won’t hesitate to squeeze the breath out of this stranger to save his life. They will not defeat him again. Not now, when he’s close to his goal he can taste it in the arid desert air. The shadow squirms and wheezes, voice thready, but it filters into Shiro’s confused brain and triggers an emotional response.
“Shi-Shiro. It’s Keith.”
Shiro’s hold slackens as a horrible understanding crashes into him.
Keith.
He’s almost injured Keith.
The one person who matters more than anything in this world, this universe, this reality. The bright light that has guided him home.
Shiro’s knees buckle, and he slumps down like a marionette with its strings cut. In an instant, Keith shifts and kneels next to him, putting a hesitant hand on Shiro’s flesh shoulder. He’s glad Keith’s not touching the prosthesis. Most days, he wants to rip the thing off and leave it in the dust, sickened by the artificial reminder of his captivity, but he knows that a soldier can’t afford to give up a fighting advantage, so he keeps the artificial arm and holds his disgust in check.
“Takashi, it’s me. You’re safe. Do you—do you remember me?” Keith’s voice breaks on the last question. He doesn’t sound like the cheeky cadet that loved teasing Shiro at all. Clearly, Shiro’s not the only one transformed by his year-long absence.
“Say something. Please.”
Shiro knows he should keep his hands off Keith, that he deserves better, not this broken half-monster he’s become in order to survive, but he’s pathetic and weak and desperate to touch, so he enfolds Keith in a hug and buries his head in the crook of Keith’s neck, inhaling the sweet smell of spicy chocolate. A rational fragment of his mind running in the background notices that Keith doesn’t resist and sinks into the embrace willingly. Tears of gratitude burn a path down his cheeks and fall into this lap with a splash louder than a clap of thunder.
“Takashi,” Keith whispers and brushes the dampness away. His hand is warm and soft and tender. No one has touched Shiro with tenderness in a year, and the gesture only unravels his loosely stitched soul further. The silence between them swells, unpleasant and ready to burst, until Shiro clears his throat once, twice, three times to spur his half-atrophied vocal cords into working.
“Keith.”
