You follow Crockpot to the field of wheat. It isn't a long journey- as it seems you have gained the trust of some of the mycelium, they sit on your shoulders and stow away in your pockets, enjoying the carnival attraction your body has become. Crockpot sits atop your head, surveilling the land.
"These crops allow us to feed the Scarlet One. We don't need them to survive, mind you, we get our energy from the Night Light, which is ever present, and our homes in the city of Portabella, to the East."
The Night Light... perhaps he is talking about darkness? It would make sense, since the only light comes from small holes seemingly poked in the ceiling above.
"Where did you guys come up with these names, anyway? Night Light, Scarlet One..."
Crockpot shrugs. "These things, we just wake up knowing."
"Okay, then when did you guys wake up?" you ask.
"You know, we had a Blood Giant once come down here and ask us the same questions. She told us that, in the Outer Wilds, Blood Giants measure time by the cycles of something called the Sun. We don't do things like that here- we simply live our lives on our own cycle, something that each Mycelium knows intuitively."
"You've had other Blood Giants come down here? Were they Iwiw and Mau?"
"No no, we've had one other. But she hasn't visited us in..." Crockpot pauses to think. "I suppose in Blood Giant terms, many suns."
Who could have visited them down here? You think about your Grandparent's house- the small parties they used to have for birthdays, their scholarly traveller friends they would invite for brunch, but none of those people ever came to your Grandparent's bedroom, let alone walk down the stairs into this odd place.