Leareth picks up the computer usage skills and the geometry simulation a lot faster than he's picking up English. Earth's current understanding and theory on physics is a lot more advanced than what he had managed in Velgarth, even over millennia; he doesn't think any of it contradicts his own understanding, it's mostly that certain confusing physical phenomena were only discovered once Earth's technology had advanced to a certain point. And Velgarth, for the obvious reasons, never made it that far. 

The math behind it is complex and elegant and beautiful – and there's no particular loss or anger associated with it, unlike literally everything else right now.

Even studying the Silmarils under Fëanor's supervision is painful, because he keeps imagining how awed and curious Vanyel would be. Leareth manages half an hour of this and then delegates that entire side of things to Nayoki and Savil. 

He very responsibly stops working at a reasonable time, puts thorough shields on whatever room they offer him to stay in, and tries to sleep. This is not especially successful, and well before Earth's dawn, he's back in the lab on the geometry-simulating software, staring at visualizations of the structure of spacetime at scales twenty orders of magnitude smaller than an atom. By the time the sun rises he has a pounding tension headache, but he's made a lot of progress on making sense of it, and he's trying and mostly succeeding at not having any other thoughts. 

Later that day, Fëanor makes a breakthrough, of a sort.

"I believe I have a working theory on the nature of Pym particles," he says. "However, to test it, I need equipment more advanced than what we have here. The particle collider in my laboratory in Valinor should be sufficient, but returning there will cost us significant time—subjective time passes ten times more slowly in Valinor compared with the rest of the universe," he adds, for Leareth's benefit.

(Also, he doesn't want to go there, specifically—the particle collider, being much too big to fit in the palace, is at his estate in the foothills of Aulë's country—Nerdanel's estate, now, and he's not sure whether it would be worse or better, at this particular moment, if she were among Thanos' victims.)

Fëanor was also working in what most humans would consider the middle of the night, which Leareth noticed in a distant-background sort of way and found vaguely reassuring. Leareth is wondering now if Elves just need a lot less sleep, though, because at this point he is definitely not operating at his best. 

Probably he should ask at some point if they have good painkillers here. Later. 

"The time-slowing effect seems worth avoiding! What are the capabilities that you need - I am wondering if our magic could help quickly build a sufficiently advanced setup more quickly. We were able to design and build the space capsule we travelled in with a week's lead time, and my people are more up to speed on Earth's tech now." 

"My particle collider is significantly larger than this entire compound and actually depends on some of Valinor's peculiar physics for more efficient energy generation. Even with magic I think we would spend more time building a new one here than we would waste performing the remaining experiments in Valinor."

He doesn't need to sleep much, but he knows something of human sleep patterns by now, and he knows that Leareth's are unusual, and not in a good way. "You would also—feel better there, I think," he adds. "I've never desired that particular effect, nor indeed slept long enough to notice it, but—'lands there are to west of West, where night is quiet and sleep is rest,' as the song goes."

Leareth gives him a briefly-very-suspicious look when he says the last thing. "All right. I expect it makes sense to leave most of my people here, then, where they can continue working with the other Avengers and getting up to speed on various things here."

After a brief pause, "- I would bring Shavri and Yfandes, I think, if that is acceptable. I am not sure either of them would be useful for the research aspect, but - they would benefit from the effect you describe." 

"Our ship should be more than large enough to hold our research team plus three others. It is not designed for...horse-shaped people, but it isn't a long voyage. I'm ready to leave immediately, if your friends are.

"Also, we should consider leaving someone here to continue running the geometry simulations without the time-slowing effect—I don't actually know if it affects computers—"

"It doesn't. I can communicate with Earth's internet without correcting for it at all. We should definitely be running the simulations there, our computers are much faster."

"Alright, then we'll all go. Unless there's someone who would prefer to stay here."

Both Tony and Bruce want to go.

Leareth wants Nayoki to stay behind and, in his absence, be in charge of the rest of his people and point of contact with the Avengers. 

Nayoki isn't especially fond of this plan! 

:Leareth, I am worried about you and I would prefer you not be alone on another planet: 

:I will be in the company of many other scientists: Leareth points out, very reasonably in his opinion. 

:You know what I mean!: 

:Also Shavri and Yfandes are coming. ...Apparently Valinor is a good place for rest. The Elf scientist thought I would - feel better there, is what he said: 

:Huh. - How much did you sleep last night: 

He wasn't especially keeping track, and shrugs. :A little: 

She's tried to have this conversation about a dozen times and it's always like pulling teeth and never seems to go anywhere. Although, Leareth does seem...more like himself, at least, since arriving on Earth. 

A little. She still has no idea why he delegated the Silmaril study to her, especially given that she's much worse at it than he is. And he hasn't, once, sat down with her to talk through his strategic-level plans, which is very weird for him. 

Nayoki sighs. :Well. Good luck with the experiment, I suppose: 

:I hope it is informative: 

And, at this point, he had better actually ASK Shavri and Yfandes about going to Valinor. 

...Shavri has no idea why Leareth wants to invite her on a scientific mission to another planet! 

She's not going to question it, though. She doesn't have enough to do here. 

Yfandes is unsurprised. She thinks she understands why, though she can't put the reason into words. 

And she's glad of it. Being near Leareth hurts; still, it's in some strange way less lonely. 

The three of them join Fëanor's team for departure. 

They load some of the equipment they've built on Earth onto the ship and then board, flying eastward over the ocean. Midway over the sea they suddenly turn around and fly westward, and suddenly it's nighttime and they're flying over a completely different ocean towards an unfamiliar landmass whose east coast is dominated by a massive mountain range.

They fly over the mountains, well inland, to a village of stone houses with red roofs, in the foothills of a more modest mountain range. They land on a grassy flat spot outside the village and disembark.

Everything in Valinor is impossibly beautiful and perfectly tranquil. The stars overhead seem to shine with supernatural brightness and clarity; there must be millions visible to the naked eye. The air, in this tropical region, is admittedly a bit muggy—with a breeze it would be perfect, but the god who manages the breezes is currently dead. The air is filled with the haunting, mournful singing of bereaved elves; they have been singing continually since Thanos Snapped, three-and-a-half local days ago. They will not stop for many more.

Leareth suddenly realizes just how tense he's been for the past month, and is finally able to relax. He starts to feel drowsy almost immediately.

Shavri and Yfandes feel somewhat better, although being here doesn't bring back Randi or Vanyel. But it's a dull emptiness their absence leaves, now, not the raw pain of an open wound.

Shavri's instinctive reaction to the change is to be offended, even angry. That was HER pain. What does this world think it's doing, taking that away from her.

The singing is beautiful. Vanyel would love to hear it - 

- Vanyel, if he knew that she were here, wouldn't want her to cling to her grief, even when offered this respite. Randi wouldn't want that for her either. So many lost, but the part that matters now is that there's hope. That they might be able to fix this, if they're brave enough and clever enough. And rest will help with that goal. It's what she would tell Vanyel, anyway, if their positions were reversed. 

Damn it, but she misses him, and Randi, and Jisa, she's barely even been able to think about that particular aching grief. Here, apparently, it's easier. 

Shavri looks over, notices - more with Healing-Sight than through her actual eyes - how Leareth is suddenly trying very very hard not to visibly sag with exhaustion. She makes eye contact with Yfandes. 

Yfandes entirely agrees on this point! 

She Mindspeaks the three Elves plus Tony and Bruce. :Leareth's going to insist he's fine, but I'm worried he might straight-up collapse if he tries to keep going much longer. He...hasn't been sleeping much lately. Can one of you help me out and insist firmly that he get some rest?:

That's too many stars! It's very unfair, Leareth is having emotions now and it's terrible timing. It's also an especially inconvenient moment to be suddenly falling asleep on his feet, when there's WORK to be done and they can afford delay even less here than back on Earth because of the stupid time-slowing effect... 

He wants to show Vanyel the music and the stars, and everything hurts - in a different way than before, it feels less like his insides are made of spiderweb-cracked glass with occasional loose shards catching him off guard, but he's...aware of it, fully, in a way there just wasn't space for before, and this is also the worst timing to be distracted about that. 

:Where are we going next?: he asks Fëanor, at almost exactly the same moment that Yfandes is Mindspeaking the group in parallel.