|First Prize for the Worst Witch|
|ISBN||ISBN 978-0141355092 or 0141355093|
|Previous||The Worst Witch and the Wishing Star|
|Next||You're at the last book|
Mildred is on her way to Cackle's Academy for the Summer Term of her fourth year. As she flies over a circus tent, her dog, Star, hides in her luggage. She then catches up to Maud. Mildred tells Maud that she has had swimming lessons in preparation for the Academy's new swimming pool. They then talk about the Fourth Year First Prizes, which are awarded at the end of the year. Maud is going for the team spirit prize, while Mildred admits that she'd like to be Head Girl, and they both laugh about how unlikely it is.
Meanwhile, Ethel and Drusilla are also on their way to the Academy. Ethel is unhappy about Mildred's recent improvement in flying, thanks to her dog, Star. Drusilla tries to cheer Ethel up by saying she'll win all the prizes, and that she will definitely be Head Girl, as every Hallow that has gone to Cackle's has been Head Girl. Drusilla then drops her hat, and when she goes down to get it, she finds a poster.
At the Academy, Miss Cackle announces that Mildred's class will be the first to use the new pool, since Mildred (and Star) won it. They get to the pool to find it full of water plants and pond life; according to Miss Hardbroom, this is so they can use it for nature studies as well as swimming.
The next day, Mildred is called to Miss Cackle's office, where Miss Cackle and Miss Hardbroom show her the poster that Ethel and Drusilla found- it is a lost dog poster for Star, who is actually a circus dog. Miss Hardbroom says that Star will have go back to the circus as they are his rightful owners.
In class, the fourth years learn the spell used to enchant flying broomsticks, and try it out on different kinds of brushes, such as a toothbrush, hairbrush, and dustpan and brush set. Drusilla then overhears Mildred telling Maud and Enid that she saw the circus on the way to school, and tells Ethel. In their next flying-spell class, Enid is flying on a feather duster she enchanted when Mildred is summoned to Miss Cackle's office again. Thanks to Ethel, Mr and Mrs Brilliantine, the owners of the circus, have come to collect Star, whose real name is Binky.
Without Star, Mildred has to fly with Tabby again, and her flying becomes as bad as it was before. After waking from a dream about Star, Mildred decides to visit him at the circus, and Maud and Enid decide to go with her so she doesn't get lost. They find Star at the circus, but are caught by the Brilliantines, who are kind and let them stay for breakfast. They look around the circus and meet the other animals, a fat pony and an unhappy looking seal. The Brilliantines explain that Binky (Star) is their star act, and that they would be willing to let Mildred have him back if they could find a replacement act.
Mildred keeps thinking about the animals, and a few days later, she comments that she wishes she could ask the animals how they feel about being in the circus, and Maud reminds her of the talking animal spell she did the previous year. The next morning she goes to the circus again, and casts the spell on all three animals to make them speak. The seal says her name is Selkie, and that she wants to go back to her colony at Grim Cove. The pony's name is Merlin, and he was sold when his owner went off to boarding school. Mildred promises the animals she will rescue them somehow.
She remembers what the Brillliantines said about letting her have the animals if they had a replacement act. Enid comes up with the idea to offer the Brilliantines the flying brushes in exchange for the animals. Mildred takes toothbrushes from the bathroom supply cupboard, and Enid takes a yard broom and the dustpan and brush. The Brilliantines are impressed with the brushes, and agree to trade for the animals. Mildred uses a transference spell to send Selkie the seal to Grim Cove, and take the other animals back to the Academy.
In the staffroom, Miss Cackle and Miss Hardbroom are discussing who should win the end of term prizes; Miss Cackle wants a prize for Art, but Miss Hardbroom thinks it's not appropriately academic. Miss Bat them comes in, dripping wet and wrapped in a towel, and claims there's a seal in the pool, and Miss Cackle wonders whether it's time for Miss Bat to retire. They then see, from the window, Mildred and her friends returning with the animals, and Miss Hardbroom materialises down to meet them.
The three girls are taken Miss Cackle's office, while a first year, Dulcie, is asked to mind the pony; It turns out that Dulcie was Merlin's former owner. Mildred hands over the letter from the Brilliantines, and the teachers realise why there is a seal in the pool, and Miss Hardbroom transfers Selkie to Grim properly this time.
Miss Cackle lets the girls go, but Miss Hardbroom wonders what Mildred gave the circus in exchange for the animals. Ethel wants to know, too, and she Drusilla visit the circus, and tell Miss Cackle and Miss Hardbroom about the flying brushes, but Miss Cackle says that if the circus owners are happy, then it's all fine. She then suggests to Miss Hardbroom that Mildred could be a candidate for Head Girl, But HB still favours Ethel.
At the awards ceremony, Mildred and Enid bring a crossword book to keep them occupied as they don't think they'll win anything. Ethel wins everything, except for the Team Spirit prize, which Maud wins. Mildred is so engrossed in the crosswords that she doesn't notice when she is announced as Head Girl, until Miss Hardbroom gets her attention! Mildred then chooses Enid as her deputy. As they leave, Miss Hardbroom appears to congratulate Mildred and wish her luck as Head Girl.