They perform some more magic tests and run out of mana and recover mana and perform more tests and a second sleepover could be fun but it's decided that people can do coordinated tests in their own places and there is not actually a need for them to all be in the same place. The Maxwells' driver takes Jess home (and Maya, too, if she prefers that to staying with the Maxwells but they assure her she's welcome to stay there), then takes Sadde, Theo, and Tyler to the Farron residence, where Sadde prefers to be dropped—he'll go to his place by public transportation, he'd like to talk to the—twins?—yes, thank you, it was a pleasure meeting you.
"Potentially unprecedented disappearance of magic," comments William. "Sounds like something fun to look into, I suppose."
"It was some magical parasite and not me, magic can spontaneously disappear, someone stole my magic?"
"So, not necessarily ruled out but not the most likely thing – Kero wasn't hiding behind me at the time, was he?"
"It sounds like – foreign magical object, magic disappears over time, or magic got stolen, are probably the general things it could be? With foreign magical object seeming unlikely, magic disappearing over time being unprecedented, and my magic being stolen being worrying and also unlikely?"
"Magic being stolen would be really worrying, but I think it doesn't quite—fit? The things Kero's said about sorcerer clans and such?"
"I don't think I've heard much about the sorcerer clans," says William. "Is it that they wouldn't, or that it sounds like they can't…?"
"Well it's more that they exist? Like, why would they, unless magic was heritable and hard-to-impossible to obtain otherwise?"
"They might not have many members amongst them, and may not trust outsiders enough? I don't expect it's particularly likely they'd steal a spark from me, instead of going after someone else, though."
"Everything here has a sample size of not very many, maybe we should go after all these other sorcerers."