The girls frantically try to reignite the Founding Stone, and Ethel and Mildred are surprised by their family history. Halloween celebrations mask the magical mayhem as the castle starts to freeze. Ethel decides to make a sacrifice.

It's Halloween, but Mildred's more interested in meddling in Miss Bat and Mr Rowan-Webb's relationship. Her good intentions backfire when her love spell goes wrong. Sybil gets caught up in Ethel's plan to get Esmerelda back in school.

Miss Pentangle brightens the gloom at Cackle's by teaching modern witching workshops, but Mildred is determined to see Miss Cackle reinstated. Sybil finds the workshops too much and Mildred takes a risk to help Miss Cackle.

Miss Cackle goes to meet her fate at the Magic Council and Mildred is determined to help her. The first years are unimpressed with Miss Hardbroom as acting headteacher and decide to soften her up.

Maud is stressed out directing Miss Cackle's birthday show so Mildred and Enid try to help her but accidentally turn her into a baby. Miss Cackle struggles with pressure from the Magic Council.

Mildred can't understand why the girls are so scared of collecting potions ingredients in the woods until she comes face to face with an unusual creature. Sybil gets a surprise visit from her big sister and Miss Cackle struggles to deal with the guilt of seeing non-magical Esmerelda.

Enid takes a practical joke too far and is threatened with expulsion. Mildred turns herself into a bat but can't remember how to turn herself back. Clarice struggles to understand the appeal of practical jokes.

A lesson on family trees gets Mildred thinking about finding her dad. Ethel can't resist making a cruel joke at Mildred's expense. Sports Day pushes Maud to take desperate measures.

Mildred makes a stand about equality when a mysterious witch arrives in school. Miss Bat's chanting performance reveals a secret about her past. Beatrice's allergy is exposed with disastrous consequences.

Ethel gets more than she bargained for when her clone spell spirals out of control. Mildred goes in search of the Founding Stone. Miss Hardbroom grows increasingly suspicious of Miss Mould.

Mildred and Ethel are more at odds than ever, so Miss Cackle sets a friendship trap on them, pushing them too close for comfort. Miss Hardbroom is suspicious of the mysterious new art teacher.

It's the first day of term and Mildred is feeling positive... until she has a hand in a wing of the school falling down! Enthusiastic new first years arrive and nervous Sybil Hallow is terrified. Mildred stumbles upon something very important.