"Colony planets? You have FTL? If it's going to keep making more people we'd be even less likely to be able to take you, but with FTL we could maybe do it? Is there a way to make it stop making more of you?" 

He shakes his head. "I am stranded on an island, remember? Space travel crystals are rare we don't have any, though a different person might be able to grow one. And we wouldn't bring the crystal that is cloning us, we would leave with two or three of our number to care and explain to future clones."

Well, that's unfortunate. "I'm not sure how much we can help you, then," she admits. "I'd still like to hear about your magic?" She glances at the crystal growing out his arm, still somewhat discomforted by it.

"We might think of something we could do in exchange, if it seems worthwhile. We might also meet another helpful alt who might be willing to help."

"We would be willing to trade our crystals for less, materials, medicine and even different kinds of food being the most immediate needs. We would like means to leave the island, but we know those don't easily fit through the door."

Then he starts explaining. The magical crystals are from his world, they can feed off the light of certain stars or from life being fed to it. Individual people can produce empowered (usually colorful) crystals with specific powers - usually just one, but sometimes a few related powers. If you embed a crystal on you, you can control it and it's powers. You can also make it grow controllably, and you can encase another object into crystal and then turn them into crystal while keeping its composition data inside the crystal, which can be used to create duplicates. Duplicating empowered crystals from other people is possible, but hard.

"Those things we might be able to trade," she agrees. 

She listens to the explanation.

That does sound very useful. She has some questions, though - what does he mean by 'feeding life to it'? How does one produce crystals? Could the Amentans learn to do it? If not, will they be able to control them? What does the one in his arm do?

Crystals can absorb energy from living things, though this is not dangerous unless you have someone actively use the crystal to more actively absorb life energy. Crystals naturally grow when exposed to light, thought at a very slow rate if it isn't the right kind of star. And also when they absorb life. One can take control of a crystal by touching it and willing it to take "root" into you. He waves his arm. Which lets you make it grow faster. Most crystals in his arm are his own, and protect the use from magic, though this one is from one of his clone-brothers, and it disrupts magic, while this one is from his clone-cousin (it's still dark, but with a red sheen to it) and absorbs kinetic impacts.

He is not sure if aliens can do his magic, but he would expect it to be all-or-nothing deal.

Could they test it, before they make any trades? ...She's not entirely sure she wants one of those in her arm, admittedly. Maybe one of the others would be willing to try it? 

They could leave it most of the crystals under the skin and it doesn't need to be the arm. Or not have the crystals inside most of the time at all, though it hurts more that way. And he will absolutely test it before the trade, it will probably take an hour to teach the basics on crystal manipulation either way.

Them being in her arm specifically wouldn't be the problem, though if they were visible that would also be a problem. She could try it, though? 

You can get it pretty discrete under there, Henry just prefers not to. And they could, yeah, it might take a few minutes to get it right... does she have anything to trade?

She has her pocket everything? She shows it to him. 

She also has her new magic, though she's not great with it yet. She has three spells: Frostbite, which lets her pour cold out of her hands; Clairvoyance, which leads her in the direction of what she's looking for; and Oakflesh, which coats her skin with a defensive layer of magic. She can get the others, too, to see what they have, if none of that seems useful to him. 

Could the Clairvoyance one be used to find the best way out of the island and back into civilization? He is interested in knowing about the others as well.

It could, if there is one, she believes. She would have to physically go to the island in question, though, and follow the trail to whatever it finds herself to show them where it is. It should be pretty obvious whether that's going to work just by opening the door - it doesn't work if the door is closed, she checked - and having her cast the spell. If there's nothing, no trail will show up.

She can introduce him to the others as well, if he wants. They're just at that table over here.

Sure... he can introduce her to his others, one of which is over there.

An identical young man waves at her.

Though, there isn't much difference between knowing one or all of them.

She stares, a bit.

(She's only encountered the one pair of alts thus far, and she's still not used to the idea of two people who are essentially the same except for what differences their worlds cause, let alone clones.)

(Also. They're very attractive, despite the alien-ness. Or maybe helped along by the alien-ness. The potential differences are interesting. She does her best to shake these thoughts away, but it is spring.)

She waves back. 

She'll lead the one she was talking to over to the table Isteri and Patiri are seated at, and the other one as well, if he'd like to come along. She'll give introductions, and a quick overview of their conversation thus far.

"Hopefully the Clairvoyance spell finds something to latch onto from the door," she tells them once that's done. "But there must be other things we can trade, assuming the crystals work for us," she adds.

Patiri and Isteri will tell her later on their considerations. Introductions happen.

"I bet there is some kind of early celestial navigation how-to that we can acquire for you. Or ship-building. Or just about anything that's not as trivial to derive from first principles on a remote island."

"Well, on a personal level, it sounds like we found a way to create gold."

(Henry nods.)

"If we can scale... well, I am not sure how to quantify how useful it is. Do you have any idea how rare a FTL power is like? If I understood correctly you need to find the right person?"

Henry nods and then says. "I am not sure at all, but less than one a thousand? But I am not sure if it's one in ten-thousand or even less than that. Are either of you interested?"

Isteri considers, winces, and shakes her head.

Patiri is interested.

And Lia had already said she'd try it. Should they check if the Clairvoyance spell works first, or test if they can use the crystals? (Honestly if it does latch onto something she might just lead them to it whether they can use the crystals or not. She's not heartless.)

That's very kind of her and it sounds better to check first. If it doesn't work he will teach her just for the information that it doesn't work.