"...hiding? From what?"

"People are mad at Uncle Savo," she says.

"This is just our vacation house," says Ror, "it's a bit more out of the way, we're not in hiding."

"...people?"

"Everybody," says Zazi, "he did a bad thing."

"He was trying to do a good thing, little one -"

"It was bad."

"I know you don't like it."

"What was it?"

"He made all the food dirty," says Zazi.

Ror sighs.

Blink.

"I'm not sure how to explain to an alien," says Ror. "It's complicated."

"Could, er, he explain it?"

"Savo? Not better than me, I think, and he isn't here."

She rubs the back of her head. "Well, could you try it anyway?"

"How about not in Zazi's room."

"Uncle Ro-or -"

"I don't want the alien to think badly of your uncle Savo, little one, and she doesn't know him -"

Zazi grumps but gets out of the way for him to motion Kaede out of the room.

She follows.

It's a nice house. There are flowered mountain slopes out the window. A servant with purple hair is dusting in one of the rooms they pass. "Lord Ror - who -?"

"Never mind, Vira."

"- yes Lord Ror -"

He leads Kaede to an office, finds her a box to sit on in lieu of a backless chair, sits down. "I'm not sure where to start."

"Well—what did she mean by 'dirty'?"

"Does your kind of alien have castes?"

"...some cultures kinda did for a long time and a very small number of them still do but it's very rare."

"Well. Everyone here has them. There's a caste considered fundamentally unclean, the - for simplicity "reds", all the castes have a few different names but they've also all got a most common hair color. Ancestral pollution from generations of handling waste and corpses."

"Uh."

"I have no idea what that sounds like to an alien, I'm not sure where to expand on it for you."

"...I'm wary of applying human biology concepts here but 'fundamentally unclean' is not a thing that would happen to people just because their ancestry handled waste and corpses. Are you—particularly sensitive to the environment, on a genetic level?"

"...you won't get very far looking for an explanation you could see through a microscope."

"—is it detectable at all?"

"No. I mean, except insofar as you can do detective work and see where a thing's been or who a person's parents are."

"...okay so why do people think it's dirty?"