Wayside School Gets a Little Stranger by Louis Sachar, 1995.
Just when you didn’t think it was possible . . .
Having finally managed to remove all of the cows from Wayside School (see the last story in the previous book in the Wayside School Series), Louis declares that Wayside School is ready for the students to return. Everyone is glad because they were all sent to far more normal schools while Wayside was closed, and they hated it. Nothing normal ever happens at Wayside, the school that was built sideways (and has a missing floor, where all the really strange stuff happens).
But, things are about to get stranger yet. The school hires a new school counselor (they probably needed one) named Dr. Pickell (or Dr. Pickle, if you prefer). He takes the job when he can’t practice psychiatry anymore because of his tendency to play practical jokes on people while they’re under hypnosis. Can he finally cure Paul of his desire to pull Leslie’s pigtails?
Meanwhile, the principal declares that “door” is a very bad word and that everyone should say “goozack” instead. Mrs. Jewls tells the children to write poems about colors, but some colors rhyme better than others. Kathy tries to convince everyone that Santa doesn’t exist. Miss Zarves (who also doesn’t exist), laments about how difficult teaching really is.
Then, the children learn something really surprising: Mrs. Jewls is expecting a baby! She has to take a break from teaching, and the children have a series of substitutes who are stranger than Mrs. Jewls. Mr. Gorf turns out to be Mrs. Gorf’s son, and he wants revenge. Mrs. Drazil turns out to be Louis’s old teacher, the one he was always afraid of, and she wants revenge. Mrs. Nogard is an unhappy person who wants to make other people unhappy . . . until she realizes that isn’t what she really wants. Wayside School may be strange, but it does have happy endings!
By the way, anyone notice what the substitutes’ names spell backward?