"Okay so-" You paused, trying to think about how to explain things to a local, and knelt down to draw in the dirt with your multi-tool. You drew a tree from its roots, then the branches going off. You circled the bulk of the tree and pointed out.
"Worlds are this middle part, here. They're big. It's not easy to draw, so imagine it looking down and it's actually a way better picture of what's going on. So, if the world is that part of the tree, it has parts of it that go up,from the top and parts of it that spread out and go down from the base."
"Roots and Branches." The observer commented idly.
"For our purposes, roots are the same as branches, though." You waved your hand.
"Doesn't matter, doesn't matter." You picked one tall branch seemingly at random on your diagram and drew it going up and up and then connecting to its own tree that was upside down. That tree then had branches that came down and got close to the branches of the first tree, but did not intersect or connect, at all.
"So, you see sometimes there's one, and sometimes there's more, but from where I am here-" You point to the tree itself.
"I don't know if I'm travelling up or down through a 'branch' that will get me to where I need to go."
"You need to go..." The observer trailed off.
"Up and down don't matter, but for the purpose of explaining, you could say I need to go down." You drew another root lengthening, then widening and connecting to its own tree with its own roots. Pointing to the circled tree you added.
"The trees themselves are like... Worlds. Bigger, I think? That doesn't matter for now, though. Point is, the worlds are like the tree when looked at from above. On different points there are 'branches' that go up and each branch is something like a plane. Smaller than a world, but it can still feel pretty big."
"What does that even mean?" The observer cocked her head to one side.
You slowed down, took a breath and backed up. "Okay... My dad and I thought at first that the worlds were the bulk of the 'tree.' But what we found-" You grinned.
"-is that branches can also be as big as 'worlds' or as small as a little plane like this one. What does that say?"
"I think it says that the actual size isn't dependent on the land but the amount of space that's all around?"
"That's true! Yeah. So, that's why we started to think that the bulk portion of the tree, that 'world' is actually much, much bigger. We just can't interact with the vast majority of it since we're stuck to our worlds by forces."
"Gravity."
"Sure." You shrugged, scratching your head.
"But that means if I go 'up' or 'down' I can get back to where I want to be."
You chuckled nervously. "Not quite. Because of what I said about size, sometimes the branches feel small and sometimes they feel like worlds, so we never actually know if we are going up or down, or simply moving up a branch of a branch towards a dead end."
The observer curled up at that realisation. "I wanna go home..."
You nodded sympathetically. "Me too."
"I'm dying before I see anything other than this stupid blue world, huh?" She asked.
You did not answer. The plane around you was alien even to you. You could not imagine what it looked like to her. The girl looked human, as most things tended to. Looking human was like its own tree. Various forms seemed to be like branches, as well, with most having four limbs and a head. The girl that seemed to be all but withering away was like you in appearance in her entirety, but with an important distinction.
