"Oooooh," says Kwispafa. "And three is halfway between three and three!"

"Gosh, so it is! I hadn't even thought about it like that!"  This kid is too cute, help.

Kwispafa bounces delightedly at having out-mathed the grownup, however trivially. "Yeah!!"

Bruce is happy to keep doing intro stats until Kwispafa gets bored or it's time to make camp, though where in this forest they're going to get enough space to build a campfire is not at all clear. Probably tons of Earth forests are like this too, but Bruce hasn't been in any of them.

Zoombinis contentedly follow their highly convenient trailblazer.

It gets closer and closer to dusk without a decent place to camp appearing, until they come to a set of five absolutely enormous trees, their trunks so close together a fox could barely slip between them, their branches tangled together like a disorganized yarn drawer. Near the base of each tree is a set of steps leading up to a little balcony in front of a little door. The sound of a saxophone drifts down from above. 

A . . . person . . . hears their approach and swings down from the upper branches to land in front of them. She (she's clearly a woman, somehow) comes up to Bruce's waist and is wearing a purple dress over a white shirt with a purple hat that's probably pinned to her . . . hair? Fur? Anyway she also has a little broom. 

"Hello hello hello!" She says. "Good to see ya! You folks looking for rooms for the night? We've got plenty of space! Well, except for you, I'm afraid," she says to Bruce, "but I can rig you up a hammock. The rest of you can just sort yourselves correctly into the rooms."

Speeba regards this entity with deep suspicion.

"Sort ourselves... how," they say warily.

"Neatly! The rooms will make it obvious. I'll go get that hammock." She leaps eight feet straight up, grabs a branch, and is gone faster than you can say, just to give a random example of a short word, "squirrel".

...are the rooms in fact making anything obvious? Or are they just sitting there inertly, waiting to reject innocent Zoombinis for unknown but eventually logically derivable crimes?

Definitely that second thing. They do have oddly Zoombini-sized furniture inside them though.

Speeba sighs.

"All right, who wants to volunteer to try one first."

After a slight shuffling of nervous orbs, Nawu hops forward and attempts to enter the leftmost door.

Absolutely nothing happens! It's a cozy little hotel room with a bunch of different kinds of sleeping furniture, a bathroom, and a table by one of the beds with a tray of snacks.

There's room in there for multiple guests. Cafly tries to follow Nawu in.

The balcony retracts itself into the tree and drops Cafly on the ground.

Bruce considers offering to stand next to the rooms and catch people, runs aground on the fact that none of them are wearing any clothes, and stands there like a dumbass trying to revert his brain to a nonexistent backup from five minutes ago.

Speeba sighs long-sufferingly. "All right, everybody, keep track of your features and let's get to the bottom of this. Cafly, try the next door?"

Cafly tries the next door.

Yup that's fine.

Okaaaay... what if Awoowoo tries to get in with Nawu?

NO. Fuck you.

Speeba rolls back and forth, deep in thought.

"Who's most like Nawu?" they wonder, looking around. "Leiwy, you have two features in common. Try following them in."

Leiwy attempts to enter Nawu's room.

Denied!

"Vapa, you have the same hair, try next. If that doesn't work, Iceso, you have the same feet."

Vapa can get into Nawu's room!

"Progress! Okay, who has the same hair as Cafly..." Speeba has the same hair as Cafly but Speeba is out here coordinating. "Kwispafa, try going in the room with your yaya?"

Kwispafa ascends.