When Dr. Bruce Banner felt his eyes burning, he decided it was best to stop researching Tony's project for the night. Even though the philanthropist insisted this idea was not only his and the credit was to be shared between the both of them, Bruce felt no desire to have recognition towards Ultron. He wasn't even sure the outcome would be a good one.

After taking one last glance at the screen before him, Banner decided to head up to his room. He didn't even know if he would be able to make it to his floor without passing out on the way up. Maybe he would rest his eyes in the elevator for the five minutes it took to get to the 52nd floor.

On the way to the elevator, he found himself humming to an old favorite song. Well, not necessarily a favorite; Just a song he would listen to stop the horrible shaking after an incident. He couldn't exactly explain what it felt like after he would turn green, and he didn't really want to. He would just remain silent until a change of conversation would take over.

It took around five seconds for the elevator to come down from the 93rd floor to pick up Bruce. You could never go that fast when you were actually in the elevator unless you had a death wish. Upon the arrival of the compartment, an exhasted smile fell on Bruce's face.

Finally, finally, finally, he thought to himself. As he was stepping onto the elevator he looked down at his watch. The fact it was 4:30 in the morning and he'd been up since 6:00 o'clock, probably had something to do with his fatigue. Quickly, he pressed the button to his floor and rested his head on the wall.

The sliding doors seemed to be going the slowest they'd ever gone, until they stopped moving altogether. Bruce was about to let out a curse in fear of the door being broken, until he noticed. A hand was stopped right between them before the doors could close.

She gave a warm smile as she stepped in with him. Her bright red hair was a mess, she had on a baggy hoodie with simple grey sweatpants, and the cut from the big fight earlier was still fresh on her face. He tried to get her to let him clean it up, but she had refused.

"Was that 'Casta Diva'?" Natasha asked, pressing the number 22 button. It made Bruce feel bad because she would have to wait longer to get to her room. He nodded quickly, forgetting that meant she had heard him humming horribly. He decided to not bring it up.

"You enjoy opera?" Bruce questioned in return, instantly thinking he sounded idiotic. Nat grinned sadly, in the way that would usually go unnoticed.

"I know all the classics," she said humorously. "From Joan Sutherland to Sergei Prokofiev." He had never heard of Sutherland, but Prokofiev sounded familiar. He grinned at her probably too wide, but he didn't care. It took a couple heartbeats for Bruce to understand he was just standing there smiling at Nat in pure awkward silence. He looked away and tugged at his brain to say something else.

"Thanks for trying out the uh-" What were they calling it? Oh. "The lullaby. I probably would have ran into the forest and messed up some trees or something." Trees? Jesus Christ.

"How horrible it would have been for those poor trees," she laughed. He thanked her silently for having a good sense of humor. "And you wouldn't be the one to destroy them. " He cleared his throat awkwardly.

"We're not really that different," he explained, trying his hardest to sound a bit amusing with his words, but it didn't work out as he spoke. "He just has green skin. And abs." She shook her head while looking away from him.

"You guys are different. You're separate people," her voice faltered on the last word. "He's not even a person. How I look at it, the big guy is just a reaction- only an emotion. You are a living human being with philosophies and lungs and an actual life. He is only a small portion of who you are. Does that make sense?"

The whole time she was speaking, sharing this intelligent and hopeful theory, Bruce kept his eyes remained on the floor. Just as he was about to reply, the elevator beeped. When the doors slid open and he began to walk out, he turned to her.

"It makes perfect sense," he told her. "But it also is told from an optimistic point of view." Science and optimism didn't work very well together.

"Well, Banner," she began, a smile playing on her lips. "Maybe optimism is the key to your equation." He started to grin that dumbfounded grin again when she added,

"And I would love to be your optimist."

In that moment, the doors closed.