This is the first of a two-parter. Mildred fails a potion test, she was supposed to have made a laughing potion but instead, because she believed the potion should have been green, she ends up making an invisibility potion. She is sent to Miss Cackle to explain. Mildred then decides that it's time to buck her ideas up and to make an effort to improve, which she does by passing the following potion test successfully. For the upcoming Hallowe'en celebrations, Mildred's class has been asked to put on a broomstick display. However, only one of them actually has to fly in it, and Mildred is the one who is chosen. Her broom, which was damaged during her crash landing on her first day, isn't up to the job, so Ethel lends Mildred hers, but she has evil intentions. At the display itself, Mildred crashes into the Grand Wizard, but it wasn't her fault! Ethel had instructed her broom to make Mildred look stupid deliberately...