Prompt: In which the light of Tony's arc reactor helps Bruce fall asleep at night.
Ever since the incident, falling asleep had been a chore.
He was almost afraid of closing his eyes, letting his mind drift away in a direction he couldn't steer. Few things brought him comfort at night, and he usually found himself running on an hour or two of rest and caffeinated tea.
That worked for him. No, it wasn't exactly the most ideal plan, but as long as he could rise early and do what he needed to get done, sleep was unnecessary. Sleep was for the weak.
However, since he'd been invited to make a home at Stark Tower and graciously accepted, he found that sleep came more easily to him.
Perhaps it was the comfort of knowing the home was at least semi-permanent, or perhaps that he knew he was safer here. There was something oddly comforting about the whole thing, even after the battle that'd left both the building and the city around it in ruins. Something he couldn't quite put his finger on.
Maybe it was that he wasn't alone.
It was a given, or at least one he'd convinced himself of, that he needed solitude. To be alone was his only option, or so he thought – maybe being alone made it worse.
Because he found that late at night, after the timer on the television had switched off and the room had gone dark, the soft blue glow of another man's artificial heart somehow gave his mind rest.
"I feel like such a child," he'd once commented, his voice slurred with exhaustion. "It's like I'm afraid of the dark." Despite his fatigue, he managed a small smile that Tony probably couldn't see, but he was sure that the other was wearing his signature smirk.
"Hey, everyone's got to be afraid of something." Bruce felt the loose arm around his shoulders tighten a bit. "But you're not afraid now."
"No." Bruce inhaled the cool night air that drifted through the window, sinking into the cushions of the sofa. "Somehow this is all very… comforting."
"It's me, isn't it?" Tony asked, chuckling softly. "It's me. Ever-comforting Tony Stark."
"More like this." He tapped the blue sphere on Tony's chest.
"Oh, I see how it is." Along with the soft glow of the arc reactor, Tony's laugh was refreshing as well. "Using my lifeline as a nightlight."
"May as well add that to your title too, while you're at it."
"So," Tony paused for a second, "Genius, billionaire, playboy, philanthropist, and nightlight?"
Smiling, Bruce leaned into Tony's shoulder. "Yeah. Just don't go around offering your services to anyone else."
"I don't think anybody else deserves it, anyway."
And with that, for the first time in he didn't know how long, Bruce fell asleep, knowing that he wouldn't be alone in the morning.