Yfandes can drink from it if he sort of pours it carefully into her mouth, and she tries to convey this by holding her head at the right angle for it and lipping at the mouth of the canteen.  

Then he can do that. "Uh, nowhere's entirely safe but a lot of places are safer than the middle of the desert, Mahdi could drop you in, I dunno, a mountain valley in Andoran somewhere."

:I need to be alone: The awful tension seems to be about to rip her head apart, and she can't even think about Va- no, stop, can'tcan'tcan't. And Hagan has a point, running off alone into the desert is stupid. :If that would be safer then I appreciate it: 

He takes off, flies back to Mahdi. "Can you get her out of here to somewhere where she can be alone - safely -"

"For how long -"

"No idea. I figured - some mountain valley in Andoran we flew over once."

He gives himself flight, too, and follows Hagan over to Yfandes. Teleports with her. 

Teleports back twelve seconds later. "What the hell -"

"No idea but it won't be improved if she dies of exposure, right? Can you get me back down to close the door on Leareth -"

"That depends on whether Van's up for refilling a spell slot."

They land beside Vanyel. 

Vanyel hasn't reacted to any of the spells cast on him. He's crying, silently. 

Fazil glances helplessly at Mahdi and Hagan.

"Van, can you refill my Dimension Door spell slots? We need to arrange something more secure for Leareth if it's going to be a while before we talk to him again."

"Mmm?" Someone said words, which included his name. Vanyel tries, with great effort, to drag himself back to the present moment. "Wha...?" 

"Dimension Door spell slots. So we can secure Leareth."

Focus. He can do this. Spell refill. 

It takes Vanyel multiple tries before he can focus enough to refill the spells, but he manages it eventually.

"You should bring him food. And - it's not a good environment to hold someone in for a long time at all really, where would he piss -"

" - right. That's a good question. We won't try to keep him there for days, just - just while we get oriented and Van, uh, recovers."

"The worst case scenario is that we have to ask the church in Sothis for help," he says quietly. "I think under the circumstances they'll have an interest in holding him securely too."

"But they won't care at all about whether whatever thing he's trying to do back home is a good idea, or whether there's something here that'll stop him from committing mass murder to do it -"

"I acknowledge that it doesn't seem ideal."

Mahdi Dimension Doors back down to the room where the demiplane is.

Walks over.

"Do you have more context than us on Companions."

Leareth, who's been focused on looking at the stars to avoid panicking about being stuck in a gravity-less room where his magic doesn't work, twists around and focuses on Mahdi. 

"They were the creation of a god or perhaps multiple gods, eight hundred years ago at the Founding of Valdemar. The first King wished for a way to keep his government stable across the generations. Companions are supposed to Choose people who are unusually good - and magically Gifted, generally - and help them to stay that way. Valdemar has in fact remained very stable for eight centuries, which is not unimpressive, really. My suspicion is that they are based on the template of reincarnated humans, but with some modifications, for the Heraldic bond and - probably in other ways. I have not interacted much with them, but they are god-created beings, and therefore I predict they are made inflexible in certain ways, that help them to be as - incorruptible - as they reportedly are." 

Nod. "Heraldic bond?"

"They form a mental and emotional bond with their Herald, not as deep as a lifebond - do you know what that is? - but close. I suspect this allows them to nudge their Heralds effectively in the preferred directions. Most of the time. Vanyel has seemed more independent-minded than I would expect of a Herald."