Xenian. Non-human, Mycroft recalls. Apparently at the bottom of the privilege pile here in Baedal. Personally he thinks sentient non-humans aren't any stranger than humans who can use magic or fly. For that matter, plenty of people in the real world have treated both himself and Sherlock as though they were somehow supernatural or inhuman—perhaps that's why it's not the abilities and physical forms that bother him. It's the absence of rules, the absence of logic: one thing doesn't seem to relate to the next. There are no patterns to observe, no way to predict danger or safety.

One reason he's come to the library today is to attempt to find out what, exactly, the rules of this place are. It must have some. There is still gravity, after all.

"Yes, I'd appreciate it, thank you," Mycroft says, polite despite his half-second of distraction. "Shall I wait here?"