"I mean how does a person being imaginary work? Do you just mean, they're a resident of her mind like you who features in imagination-generation, or do you mean they are - fictitious themselves somehow?"

"I mean they're characters in her daydreams and speculations and that's why they exist. For example, Riley used to have an imaginary friend and he helped me and Joy get back to Headquarters. He's dead now. And recently she's been imagining having a boyfriend a lot and Joy made some copies of him to help us get back to headquarters. They died too. The copies, that is."

"How did they die?"

"Bing-Bong was on a ledge that collapsed when Family Island did. The boyfriends- Joy got them to stand on each others' shoulders to make a tower with her on top, then throw themselves forward at just the right moment to get her to the cloud I was on and push us both straight towards Headquarters.

Joy isn't good at noticing the downsides of things."

"I... see. It seems odd for imaginary people to be subject to falling."

"Why?"

"- if Riley imagined them again, would they just be similar people, or would she bring them back to life?"

"She could imagine similar people again, but not exactly the same people.

Oh- an imaginary person could have fallen to their death and survived if they'd done it all in Imaginationland, but these ones fell into the Dump."

"Can everybody in Riley's mind die?"

"I don't know. So far only imaginary people have died but so far only Joy has fallen into the Dump and survived, and she managed to get out again pretty quickly."

"What's the Dump, besides what it sounds like?"

"It's a pit where we throw stuff that isn't worth the space it takes up other places anymore- obscure knowledge, unimportant memories, imaginary stuff that isn't being used anymore, and so on. Stuff left there mostly eventually vanishes, some things quicker than others."

"Space is limited?"

"Yes. Around nine square miles."

"By... what?"

"Riley's mind is round- go far enough and you come back to where you started."

"So it's not enclosed, it's space-warped?"

"Yes."

"Huh. Has it always been that size?"

"No, it gets bigger over time. But only slowly."

"Huh. What does an imaginary person who doesn't fall down and doesn't get imagined any more do?"

"Bing-Bong traveled around Riley's mind and collected old memories after Riley stopped imagining him, but I don't know if that's normal."

"Don't explore much?"

"I don't. It always seemed like too much effort. And too much of an imposition on everyone. And recently I've been busy."

"- are you yourself generally sad?"