The Professor will wait for an appropriate lull in the conversation, but eventually he asks, "Not that I don't appreciate the advance of medical technology, because I do, but I'm a bit concerned as to whether there are likely to be any direct consequences, negative or otherwise, to one of my students having summoned a demon."

"Well, I can't say for sure, but apart from the obvious presence of said demon it's possible that when she dies she'll become a daeva. I have never heard of anyone turning up in any of the daeva realms claiming to have come from nearly two centuries earlier in a world with mutants, so it's probably never happened that way before, but perhaps this is literally the first time anyone here has managed a summons in the first place."

The Professor flinches slightly, raising a hand to rub his temple. "She seems particularly distressed by this prospect. Is there any way of reversing it?"

"No. But it might not take effect at all; like I said, nobody from this world has ever seemed to appear in mine that I know of. And if by some well-kept-secret people here are attached to my set of postmortem options, being a daeva is much better than the alternative."

"She's distressed by the possibility of being separated from her loved ones, apparently." He doesn't look unsympathetic to the concept.

"Well, if I can be dismissed and resummoned normally other people can also summon me and share it around. Although there's also no way to guarantee that they'd all be the same kind of daeva, and visitation opportunities are few."

"She's also distressed by the possibility of denying her father the opportunity to see his mother again, if our universe has a native afterlife. She seems to be seeing it as being stuck between a rock and a hard place."

"I'm really very sorry about that, but I'm sincerely unaware of a workaround even if we assume everything I know about my world applies here, and I think you understand that I couldn't reasonably warn her in advance."

"I understand. But that one, I can't fix."

"I don't object. Although in case I can't come back, do you suppose she'd mind waiting until I have a chance to terraform Mars? I've always wanted to terraform Mars."

"I imagine she'll be willing to wait."

"Cool. I will hang out here, chat with Dr. McCoy about medicine and give him more books, and then fly to Mars, if there is no objection."

"No, none."

Edie is waiting when he gets back.

"Hi. Unless Dr. McCoy has more medical questions you can get rid of me now."

"And how do I do that? And how does Emily summon you again?"

Cam hands her a piece of paper. "Summoning instructions. Don't deviate from them. You get rid of me by concentrating for about a minute. I really am sorry about the surprise potential afterlife complication."

"...If your world is wholesale hooked up to my world's afterlives, your grandma will be in Limbo, and you will be able to send and receive mail wherever you wind up."

And eventually no more demon.

And Emily draws the circle to resummon him.