Once every seven years, it is Wish Day at Cackle's, following an ancient tradition when the pupils are allowed one special wish at the magic well in the forest, a magic wishing well which will grant any wish written on a pebble thrown into the well. But the teachers know that Wish Day is not real. The magic water in the well dried up years ago and nowadays the teachers make the girls' wishes come true themselves. Mona doesn't believe in any of this nonsense and prefers to put her faith in science. When she is challenged by Miss Cackle, she declares proudly that she can do without magic completely. Miss Cackle accepts the challenge but when she discovers Mona cheating, she secretly zaps her with a disabling spell to teach her a lesson, and it is not long before Mona realizes that magic is actually a very valuable asset. Miss Cackle and Hettie get their wires crossed and as usual Hettie tries to save the day.