Our narrator starts this chapter with a reminder that he was in the room watching the witch conference (a.k.a. evil scheming session) go down. (Shmoop got pretty wrapped up in it all, so it is great to have that reminder.)
The narrator is freaking out because he's worried that the witches will sniff him out, but luckily they're a little busy.
In all the commotion, the narrator had lost track of William and Mary (his pet mice) and, suddenly, the other witches start to shriek in delight. They see William and Mary and think the GHW has already turned two children into mice.
The GHW tells them otherwise, but assures them that she'll find the boy who owns the mice – she's sure it's a boy – and eat him for dinner. Ick – and uh-oh.
Now the GHW must share the recipe for FORMULA 86 DELAYED ACTION MOUSE-MAKER with the other witches so that they can execute their evil plan.
With screams of "O Brainy One!" (9.20) and "She's a wonder!" (9.25) and "Your Grandness" (9.37) scattered throughout from the witches, the GHW reveals the recipe.
Some of the key ingredients are as follows: one boiled wrong-end of a telescope; the tails of 45 brown mice, fried; the mice themselves, simmered in frog juice; a gruntle's egg; a crabcruncher's claw; a blabbersnitch's beak; a grobblesquirt's snout; and a catspringer's tongue. Simple enough, right? (In case you want to replicate this at home, but have forgotten what the beak of a blabbersnitch looks like, don't worry, there are illustrations in the book to assist you.)
But wait. Where does the delayed-action come in? Well, the Brainy One came up with the idea to put an alarm clock in the concoction, set to the time that the child will become a mouse. Brilliant.
One final warning from the GHW: don't give more than one drop of formula to each child, or the child might change into a mouse immediately, and that would be a bit hard to deal with.