Flashback.
"What's wrong?" He asked.
Natasha placed the towel down and looked at him. Her wet curls hung, and she sighed.
"When I first joined SHIELD I thought I was going straight. But I guess I just traded in the KGB for Hydra." Natasha said lowly.
"There a chance you might be in the wrong businesses." He joked.
She chuckles but then, faced him seriously.
"I owe you. "
"It's ok." Steve said in a low whisper, and a weak smile.
"If it was the other way around, and it was down to me to save your life, and you be honest. Would you trust me to do it?" She asked, in one of the most serious tones ever.
"I would now. And I'm always honest."
End of Flashback.
But it was the other way around. Steve broke the promise. Now, Natasha was in a hospital bed. Life machines hooked, and heart monitor. Steve stood there with blood on his Captain America uniform.
He and Natasha were on a mission together, when she was shot. Three times. Iron man came and put her in his suit, but it could only keep her alive for 1 hour. They were in Japan.
They were now back in America and she was in the hospital. The Avengers waited outside the room. Steve stood there's he hadn't even got himself checked.
"Steve, you need to get checked. Your hurt." Tony sighed.
He didn't reply. He just shrugged his shoulders. Still looking at Natasha.
"She's fighter. She's survive." Clint said.
Everyone else left, but Steve spoke up. Clint turned back.
"What?" Clint asked.
"What if she doesn't survive? That means I broke the promise." Steve whispered.
"What promise?" Clint asked hurt.
"Back In DC. I trusted her with my life, like she did with. After Ultron, when she got hurt. I promised her that I would protect her, and have her back. Looks where's that's got me."