It's potions class and Drusilla drinks a potion and turns into a tree. Ethel points out that the dangers of turning into a tree include getting chopped down, woodpeckers, etc... Miss Hardbroom asks how they would be able to tell which tree Drusilla was if they were in a forest. Mildred says she'd be the one that dropped a branch on them. Miss Hardbroom doesn't think that's funny, and makes Mildred drink her tree-turning-into potion next. Mildred turns into something "prickly and annoying". Miss Hardbroom tells the class that they're getting a student teacher from Weirdsister College named Miss Gabrielle Gribble.