III.
Bruce brought his lunch down to the lab so he could eat while he tinkered and worked out some calibrations on his computer.
His lab—it still made him smile, even this many months later. He wasn't sure he'd ever get used to the idea that all these toys were his to play with, no matter how many times Tony assured him these things now belonged to him.
He adjusted his glasses and peered closer at the set of numbers on the screen. He was about to make the appropriate corrections to a couple of discrepancies when his cell phone jangled noisily. The number wasn't familiar, but had a recognizable SHIELD encryption on it, so he answered.
"Hello?"
The first thing he heard was a lot of gunfire and his heart skipped a beat.
"Bruce," came Natasha's voice, and Bruce frowned with worry, because her voice was strained and stressed. "How do I shut down a particle accelerator?"
There was a loud crackling noise, followed by what sounded like more gunfire.
"Are you okay?" asked Bruce. "Where are you?"
"Switzerland," Natasha bit out loudly over the noise in the background.
"The LHC?" Bruce questioned and Natasha grunted in assent. The physicist frowned. "Do you need back-up?"
"Particle accelerator! Shut down!" Natasha snapped. "Now!"
Bruce raked his hand through his curls, and swiftly began talking Natasha through what she needed to do. He spoke fast and clearly, and she gave him calm but curt replies, occasionally getting cut off only to return a few seconds later, panting.
"Should I, uh, be concerned here?" Bruce questioned.
"Just some wacko trying to make a black hole to swallow Europe," Natasha replied.
"Um," said Bruce.
Natasha barely spat out a brisk "thanks" before she hung up.
When she was back at the Tower two days later, she assured him that Europe had fortunately not been sucked up in a giant black hole, thanks in part to his world-saving advice.