The snake in a jar is preserved in formaldehyde, and it's in their biology classroom. The class has a game of daring each other to touch it for money. (Warning: do not try this at home. Formaldehyde is bad news, Shmoopers.)
Henrik, of course, is able to get his hands on it because he's the biology teacher's kid.
Poor Henrik really doesn't want to do it, but Hussain swipes it off the shelf, holds it over Henrik's head at recess, and threatens to bash him with it if he doesn't put it on the heap.
Agnes just wants them to get the heap built already, because Pierre Anthon has started spitting plum pits at her from the tree on her way to school. His latest thing is tormenting her about how she's going to marry someone she doesn't love just so she won't be alone.
Pierre Anthon may be smarter than everyone else in his class, but he's kind of a jerk.
Henrik swipes the snake and puts it on the heap of meaning, and the hamster, Oscarlittle, totally freaks out. The kids, of course, think this makes the snake even more meaningful.
The chapter ends with them looking expectantly at Henrik, waiting to see what he'll demand.