Cass squints slightly, thinking. Arcanum sounds like Arcana, so maybe it's related?

...She's not really sure about Patron, tho. Maybe it has something to do with that spell from those books about the magic school Steph likes? Arcanum, Patronum... not that she knows what any of this actually means, even if it is related.

"I don't know what... those words mean," she says finally.