A/N On my own now. I will be basing the story on what was shown but extrapolating it from there. If there are any elements of the MCU that might impact the story please feel free to comment about them, or PM me. I saw Dr. Strange once, Black Panther half that, and never saw Captain Marvel. My son reminded me of something from Dr. Strange that will change the story a bit when we get to that part, which I was unaware of.

"Remember."

"Clip all the branches."

"This one's on me."

"Three, two, one."

First stop, New York.

Not Brooklyn. Not even Queens. The coordinates from Banner's trip into the past placed Steve on the roof of a brownstone in Manhattan. The radiance of the mind stone opening the portal speared the air, drew the eye. Chitauri warriors were fighting and dying uptown, but Tony Stark was doing his best to keep them contained, with the rest of the newly-christened Avengers doing their best to wipe them out.

Avenging. Phil Coulson, the first to die for the team, before it even was a team. Everybody loved Phil. If only they had pre-venged him, not of this would have happened, but they weren't the Pre-vengers, were they?

"Back so soon?" said a woman, amusement lacing her voice.

Steve turned, to see a bald person in robes, flinging power around, driving the few Chitauri in the area back uptown. "I must say, your technology is precise, I'll give it that much," she said, still with her back to him.

He retracted the helmet into its housing. "He didn't say you were a woman."

The Ancient One turned, lacking enemies to dispatch now. "You're not Banner."

"No, I'm not," said Steve, surprised that she was surprised. Banner made it sound like she knew everything. On the other hand, she was busy. "He was wounded using the stones, and couldn't come."

She looked concerned. "Wounded?"

"His arm," said Steve, holding up his right hand. "Only he could use the stones and survive. He brought everyone back."

"I won't ask where they went," she said, warning him off the topic. Her bright, perceptive eyes scanned him. "You're the frozen one."

Not his preferred legacy. "My name is Steve Rogers."

"I know," she said, not offering any name in response. She looked at the case in his hands. "Have you come to return what your friend borrowed from me, Captain Rogers?"

"I have." Steve put the case on a nearby table and opened it, lifting out a containment grid with the green stone held in it. "With proper gratitude for the loan." He held it out to her.

She held up her hands, and the stone lifted from the grid to float between her fingers without touching her flesh. Pulling her hands back she let the stone move into the metal casing of the Eye amulet. There she paused, frowning. She pulled the stone out of the shell. "I cannot accept."

Steve kept himself very still. How could she not want the stone? It was hers. They needed her help, too, and if she didn't take back her own stone maybe that wouldn't get that either. But a commander of men learned quickly how to keep doubts and surprises to himself. Bad for morale. "I don't understand."

She floated the gem back into the grid, releasing her spell. "What I feared has come to pass, as I thought it might when I gave the stone to Banner. You achieved your ends, clearly, but the universe is now unstable. You must fix it before I can accept this gem."

"What do you mean, 'unstable'?" All mission objectives had been achieved.

She pointed to the case. "Show me the gems, so that I may assess the damage."

She'd defeated Banner easily, but the gems were Steve's responsibility now. "I will, but if you try to touch, take, or use the stones in any way I will have to stop you."

She smiled. "You'll have to try. Do not fear, Captain Rogers. The Eye of Agamotto has passed from one Sorcerer Supreme to the next in unbroken succession for thousands of years. We have learned to control ourselves around its power."

Steve lifted the case, displaying the stones. He placed the green stone's grid back in its place.

She reached out a hand, above the case but not touching it. "Yes. I can feel them." She withdrew her hand.

"Feel them?" asked Steve, closing the case.

"Yes. The Reality gem and the Time gem are unhappy, but the Mind gem is virtually quivering."

"I don't understand," said Steve. He'd been the one to retrieve the Mind Gem. "My part of the mission went without a hitch, well except that I had to fight myself for the scepter, but I used the stone on the earlier me, he shouldn't remember a thing. I know I don't."

She looked at him curiously. "Why do you think that would matter?"

"Because that's what Banner said, that we can't change our own pasts."

"If only it were that easy." She sighed. "That's not how it works. Haven't you watched any of the movies?"

Steve shook his head. He'd been meaning to but somehow never found time.

"People are changing elements of the past all the time." She held up a hand and a line appeared in the air. A bright point moved along the line until it reached a midpoint and burst, making a sphere of light that spread along the line in both directions. "Haven't you ever had a moment where you felt you should do something that you don't end up doing, and later discover that you should have?"

"You're talking about hunches?" Steve had never really had one of those, but then he usually did what he thought he should do.

She nodded. "Those are the temporal echoes of a future self, suffering for his mistake. Fortunately those are not acted on, almost by definition, but sometimes larger changes slip through. My entire job as the Sorcerer Supreme is to fix those tears. I explained this very clearly to Banner when he was here."

Steve winced. "After the mission started." And afterward, well, they were kind of busy afterward.

"A mission planned and executed with a mistaken notion of temporal echoes and reverse causality. By meddling with the stones themselves, you changed your pasts and now you will have to change them again, to set things right. Not what you or I consider right, Captain, but what the stones consider right. Come with me. We're going to have to reconsider your mission." She walked to the roof access. "Mind the floors, they've just been waxed."

Second stop, Morag...

Nebula's description of Morag was pretty accurate, considering it was third-hand. She'd gotten it from her sister Gamora, who'd gotten it from her paramour Quill, who called himself Star-Lord for some odd reason. At least Nebula thought it odd, but she thought most things humans did were odd.

The planet was warm and wet, rocky and abandoned. Some ruins remained, but the only things in them were rodent-sized lizard-like creatures. They and Steve ignored each other. Steve left his helmet up and waited.

He sensed movement in the shadows. According to Rhodey, Quill, aka Star-Lord, came dancing through the ruins and walked right into a punch that knocked him out. Cap could spot the dancing but Rhodey was motionless, until he wasn't. With Quill on the ground, Nebula searched him for the keys to the building where the gem was kept.

Steve followed them into the temple, watching as Nebula burned the flesh off her arm retrieving the orb from some kind of energy field. She handed the orb off to Rhodey as the robotic skeleton of her arm cooled. Rhodey went quantum immediately after, but before she could follow, Nebula cried out in pain.

This must be when her systems synched up with those of her earlier self, alerting Thanos to her presence here.

Steve watched stoically as she screamed, before rushing off to Quill's ship, which was also the ship Clint and Natasha had gone off to Vormir in. It wouldn't help, but Steve had other concerns. The Power stone wasn't one of those distressed by their mission, so the Ancient One had specified that under no circumstances would he interfere with how events played out.

Thanos came, took Nebula, and left. They didn't even scan for the stone, not that Steve expected them to. They had to know by this point that the stone had been taken away.

Once they were gone, Steve went to the power field where the orb had been. He held an orb as identical to the one taken by Rhodey as the Ancient One could make it. It would have been safer, and more convenient for him, to open the orb there on Morag and just take the stone, but they had no way of knowing how long that would take. The original orb was lost in the ruins of the mansion, but Steve had been there while it had been analyzed and opened. He didn't understand much of the analysis, but he remembered what he'd heard and seen, and the Ancient One understood what he remembered far better than he did.

Steve put the orb against the wall of the field and pushed. There was some resistance, but the field bent, as it had under Nebula's hand, before suddenly giving way. Steve had no idea if the armor he wore would protect his hand so he was careful not to let it go past the edge. The orb floated into the middle position and stayed there, just like before.

Steve did a quick scan of the room, and saw the set of keys lying there, fallen from Nebula's hand in her suffering. The doors had closed, so Steve used a Pym particle to make himself small enough to get out, where he put them in the unconscious Quill's pocket. He would wake up, think he slipped, and continue as he had.

Nothing changed. Like Rhodey before him, Steve raised the arm with the time-suit controls and went quantum.

Fourth stop, New Jersey...

As an earlier version of Captain America left the lab, having 'borrowed' a few Pym particles for his and Stark's return trips home, Steve replaced the tubes with new Pym particles, created by Hank Pym himself, based on his old notes. That done, he went to the basement, to return the...oh, crap.

He pushed the doors of the vault apart easily. Too easily. Tony had used his torch to cut through the bars, but then he'd run into his father and didn't seal it up again. Which was good for Steve but bad for the mission. Steve plugged the tesseract cube into the slot, but how was he supposed to lock the vault? He looked around, but a quick scan didn't reveal any welding gear.

Fifth stop, New York...

Steve appeared out of quantum space and said, "I need Mjolnir."

She looked up from her work on the Mind stone. The tesseract cube had needed only a little nudging to build itself, but the blue gem had been a part of a larger unit. Fortunately they had all the time in the world. "What on Earth for?" He wasn't supposed to need that until he went to Asgard, some steps away in their plan.

Steve reached out his hand. "Tony had to torch his way into a vault to get the tesseract." He waited for the usual histrionics but she surprised him. "Can your magic weld iron bars thirty years ago?"

That got more of a response, a huff of laughter. "I think you fail to understand what sorcery is meant to be used for."

"I didn't think so." Steve called Mjolnir to him and went quantum before she could stop him.

Sixth stop, New Jersey...

Whosoever holds this hammer, if he be worthy, shall wield the power of Thor. Steve was worthy, and he needed lightning, and the lightning came. It hurt, but he wasn't considered worthy for nothing, touching the hammer to one bar after another.

Many layers of reality away, Thor looked up from his latest tankard of ale. "What?"

Seventh stop, New York...

Steve emerged from quantum space, to see the Ancient One just about to call out to him. "Emergency handled," he said, hanging Mjolnir from the coat rack.

She sat back, warning unnecessary. "How many of these little jaunts can you make?" she asked.

"As many as I have Pym particles for."

"You just used two making a totally unnecessary trip to get that hammer. How do you plan to get back when we're done?"

"Simple," said Steve. "I brought two extra particles, just in case of something like this. If I hadn't needed them I would have just given them back."

"So someone else can shrink as you do?"

Steve shrugged. "They can anyway, but it's too dangerous. Without the base unit you'd get lost, and we'll destroy the base as soon as I get back. Scott won't ever risk it, ever again. He lost five years of his daughter's life already."

"Seems like a sound motivation," said the Sorcerer Supreme. "Speaking of motivation, it's time for your next journey."

Steve opened the case, kept closed to avoid disturbing her work. He lifted up the containment unit holding a large golden gem. "Won't be a minute."

Next stop, Vormir.

A/N 2 Their plan really had no room in it for failure of any kind. They could have put the Power gem back in the orb, put the keys in Quill's pocket, and welded the vault shut, while making the returns after a simple and uneventful mission. Not technically logical flaws, they could have become major problems easily, if someone pushed a starship through and blew up the compound, for example.

These two stones were the easiest and most straightforward to return. Things get a bit more complicated from here.