He feels an open summons and lets it grab him -
"I'm glad you think so. I'll call Gregor and invite him to lunch; that should simplify whatever intricate scheme they're concocting to get the two of you safely in communication."
"All right. This place seems... populated enough that you probably don't want me to make lunch on account of it would upset someone whose job description is 'cook'?"
"If you make lunch for Gregor, with magic, it's likely to upset someone whose job description is 'bodyguard'," says Miles.
"Someone whose job description is 'bodyguard' and suspects me of wanting to poison Gregor should really get upset much earlier than that."
"It's not about suspicion so much as procedure. Upsetting the established order of things. An established order which is designed to make it easy to verify that no one is poisoning Gregor."
"If someone suspects me of wanting to poison Gregor they should not let me near Gregor. I am not attached to the idea of making lunch, but, in principle, if the literal inability to poison Gregor is very important here, he should not be coming over for even perfectly ordinarily sourced lunch."
"Yes. I know. This is not a system that was designed with magic in mind, and it is not going to handle the addition gracefully. In the interests of preserving your future access to Gregor, I suggest that you not bring up this line of reasoning around any actual bodyguards. I can figure it out, Illyan can figure it out, Gregor can figure it out, and that is as many people as need to know."
"For the record, if any of us thought it was remotely likely that you might poison Gregor, we wouldn't be suggesting you meet him. But please don't poison Gregor. We've been doing so well with our lack of civil wars lately."
"Good, I'd hate to be unappreciated. What's for lunch? I haven't had lunch I didn't pick out in a hundred and fifty years."
"I'm not sure. I don't even know when is for lunch. Gregor has a busy schedule. Mother?"
"I'll go find out. But I suspect the answer to the second question is 'tomorrow', and the answer to the first question can be dictated within reason."
"Back home - I cannot begin to speak to here - there is an afterlife. Most dead people wind up in Limbo, which is disappointing but not too awful. Dead summoners become daeva instead."
"...I see," says Miles. "I'm not immensely eager to test this, but I suppose it's good to know."
"It's a much better deal than being a Limboite, but I don't know what you were in for absent potential intervention from my afterlife system. If it weren't for daeva running around everywhere in my world I couldn't come up with a reason to expect an afterlife at all, and - there are not daeva running around everywhere here. Or, more tellingly, there are not people from Barrayar running around in Limbo."
"Right. And there's no one from Barrayar, or - Beta Colony, Illyrica, Tau Ceti, Marilac, Jackson's Whole, Cetaganda, et cetera - running around in Limbo. And I suppose it's reasonable to assume that if we all went there, you would've run into a few by now. So. My universe is just as much of a theological question mark as it was this morning."
"Quite, except now there's a possibility you'll be hijacked by what is at least a known quantity."