"A Silmaril. Possibly something that isn't a Silmaril but the energy requirement would be astronomical. And of course if you have other wormhole generation methods Valinor does have defined coordinates in physical space, it's just far away."

"Alright, we have at least two ways of getting you home even if this goes as far south as possible. Well, one way, if Asgard got blown up and they can't do a replacement Bifröst."

"Oh, if the Valar decide to be dicks—or Thanos kills the rest of them—I can just fly this thing, it can get pretty close to lightspeed. It'll take ten years even with time dilation but it's not like that's a significant fraction of my lifespan."

"Right.

"Okay, we're coming in—how do I land this thing?"

"I'll do it. I assume you want the landing pad next to the building with the big 'A' on it north of the city?"

"You can see that?" To him the Avengers facility is just a grey spot in the distance.

"And no. We need to drop off Peter with his aunt first."

"She's gone. I looked it up as soon as I got a signal.

"Look, I know why you don't want me in this fight but we lost the first fight and now I don't have anywhere else to go if I wanted to. I'm an Avenger now, you said it yourself."

"I'm not going to risk losing you again. I'm leaving you at the Facility and that's the last I'm discussing it. The elf will keep an eye on you."

That's not his assignment at all but he isn't particularly motivated to do things for Tyelpë anyway. And he'll still be there when they bring Fëanáro back.

"Sure."

They arrive at the Facility and reunite in-person with the other Avengers. The next morning Thor, Bruce, and Nat take the Quinjet to Sokovia and Tony takes the Elvish ship to a remote spot on the east coast of England to start scouting for the North Sea Silmaril. (Flying trans-Atlantic in just his suit is easily possible but not exactly comfortable.)

The Silmaril at the bottom of the ocean is not hard to find at all once he knows to look for it.

He grabs it and flies back to shore, where he puts it in a lead-lined box and starts to de-suit.

He hears a gun cock behind him.

"Give me that. It's mine."

Immediately he's re-suited and his arm is a much larger gun pointed at the person who's pointing a gun at him, who he's pretty sure is an Elf.

"You've got to be kidding me."

"I don't want to do this. I know I can't kill you. But you don't understand. If you don't give me the Silmaril I have to try."

"I heard something about someone swearing an inviolable oath about these things. You bound by that too?"

"Yes.

"If you're not going to give me the Silmaril, kill me now. I will go to Mandos with my father and brothers and you can go on doing whatever it is you're doing, which given the circumstances is probably more important than one life."

"I'm not going to kill you. I'm not going to give you this either unless you come with me.

"We're planning to use it to resurrect someone who I'm pretty sure is your father."

"You're going to what?

"The Silmarils are more versatile than most people realize but I was not aware that was one of their powers. Or are you planning to collect all three and give them willingly to my father? That might end the Oath at least as a relevant problem but I don't think the Oath is the only issue Mandos has with him."

"No, I'm not actually sure where the Silmaril fits into the plan at all but we only need one. My friend is currently working on procuring a clone body."

Maglor thinks about this for a moment as he puts together the details of the plan.

"That would probably actually work. Now can you please stop pointing whatever is on the end of your arm at me."

"You threatened me first so not until you put down the gun."

"Put down the Silmaril."

Slowly, without moving his gun, he puts down the box containing the Silmaril.

"Take it. Just not farther than ten feet from me."

Maglor puts down his gun and picks up the box.

Tony turns his arm back into an arm.

"Come on," he says, gesturing at the ship. "Let's go. We're going to get the other one."