This plot bunny came from supesfan18. I hope I can do it Justice. As always, I don't own Marvel. I just play with them. No copyright infringement intended.

"It doesn't make any sense!" Tony yelled as he made yet another adjustment to the computer. "I need an explanation, people."

"The Quantum Realm was never meant to be used the way you people used it," Hank said as he pushed Tony to the side. "Not that I'm complaining since you brought back half the universe but-"

"You're going to complain anyway," Janet replied, a sad smile on her face. "There are many possible reasons why Captain Rogers has not returned. Has anyone checked the history books?"

"No changes there," Bruce frowned.

Janet nodded. "If he were still in the Quantum Realm, it seems likely the locater chips you installed in his suit would allow us to pull him out. If he isn't still trapped in 1945 in our reality-"

"Then he is in another reality," Shuri finished. "What experience do you have with other realities?"

"Besides knowing they exist, none," Janet replied. "We know he successfully completed his part of the mission, so it seems likely he was transported elsewhere while attempting to return home."

"How do we get him back?" Natasha asked.

None of the scientists spoke for a moment, but eventually Hope sat beside Natasha and looked her in the eye. "We don't. I'm sorry, I know he was more important to you than he was to the rest of us.. But, there's absolutely nothing we can do from this end. He would have to find his way back with the help of our counterparts. It's possible Steve Rogers doesn't even know he is in another reality. He could believe he's living out his days right here or even in our past. We can only hope he's safe."

"Safe and happy," Falcon said softly. "We can hope he's found peace, Widow. I know this is hard. I hate it, too, but these are the best minds on the planet. If they say it can't be done then it probably can't be done. We will get through this together. You are not alone."

Wanda gave her a quick hug. "I'm so sorry."

"It isn't right," Tony argued. "This plan was supposed to mean no one was sacrificed. We just defeated a mad titan bent on destroying half the universe. Cap should be here with us. This should be a celebration, but I don't feel like running any victory laps." Tony threw his hands in the air. "I'm not giving up, Red, er, got to come up with a new nickname for you or you need to make a trip to the beauty shop. I will find a way to fix this."

Natasha only nodded. "Somebody needs to tell Carol as soon as she returns."

Nobody moved to stop Natasha as she made her way to the door. It had been a difficult couple of days at the end and an even more difficult couple of years. The Snap had taken out half of all living creatures, but it hadn't been enough to stop the remaining Avengers. Thanks to their lucky break finding Scott and the van full of the Pym's greatest invention, they had travelled through time and reversed Thanos's victory. But, without Steve, their fearless leader, it seemed pointless.

Natasha walked into the locker room, grabbed a change of clothes from her locker and went straight to the shower. She needed some time to process a reality without her best friend. It still seemed funny giving Steve that title, one she had always reserved for Clint, but it was true. Clint saved her, but Steve's trust in her had made her a better person. Now he was gone.

Just as Natasha was pulling the towel around her body, the door opened to the locker room and Steve walked straight to her, pulled her into his arms, and kissed her hard. She felt so exposed, and she knew it was wrong, but she was so relieved to see him alive that she kissed him back.

They were still in an embrace when Carol walked in. "Carol, it's not what you think-" she began, but Carol cut her off.

"I see I was right about where Natasha would be," Carol smiled. "Steve made it through the portal right after I arrived. When they told him you thought he was lost, he couldn't get to you fast enough."

Steve still had his arms around Natasha's waist. It was disconcerting. "Carol, I swear this has never happened before. Steve, let go, and talk to your girlfriend."

Steve and Carol exchanged looks then stared at Natasha. "Nat, we've been married for almost four years. What's going on?" Steve asked.

"Carol's only been here for two. You've only been dating a few months," Natasha paused. "'Might not even realize he was in an alternate reality', that's what Hope said. I think I get it. This isn't my reality. I'm the one who has ended up in the wrong place."

"I don't know what's going on, but we are going to find out. Get dressed. I'll alert the others," Steve said firmly before walking out the door.

"We'll figure this out, Natasha," Carol added before following him.

This one is short by necessity. More to come. Thanks for reading.