Selection Day is the first episode of The Worst Witch (2017 TV Series). It was first broadcast on CBBC and CBBC HD on 11 January 2017 as a double length episode, counting as episodes one and two of the series. It is followed by the episode 'Tabby'.
Maud Spellbody crashes into Mildred Hubble's flat on her way to Cackle's Academy, where it's Selection Day. Ethel Hallow makes a good first impression on the teachers. Mildred helps Maud, whose glasses were broken in the crash, get to school, but they both crash-land into the pond. They tell Miss Hardbroom that Mildred was supposed to attend Pentangle's, but decided that Cackle's is better.Esmerelda Hallow, Ethel's older sister, gives the students a tour and Miss Cackle helps Mildred cope with the effects of a transfer spell. Mildred and Maud sneak off to look at the kittens and Ethel eavesdrops on them discussing how Mildred is not from a magical family. They lose a kitten, but find it in the kitchens where they meet Miss Tapioca and Miss Cackle's twin sister Agatha.
Mildred struggles with the written exam, but Miss Cackle encourages her to do what she is good at. However, because Mildred fills her exam paper with drawings instead of answers as her best subject is Art, she receives 1%. Miss Cackle gives Agatha permission to speak to Miss Hardbroom for an internet article.
The students make their potions and Mildred successfully manages to levitate, after taking some pond weed from Ethel's scales while she is brewing a dragon potion. As a result of this, Ethel wrongly turns into a worm instead. Mildred owns up and Ethel reveals to Miss Cackle and Miss Hardbroom that Mildred is from a non-magic family. Mildred automatically fails her practical because she interfered in the course of lawful spell-casting.The girls are told who passed their entrance exams. Maud and Ethel have made it in, but Mildred hasn't. She and Maud say a tearful goodbye. On her way out of the castle, she sees who she thinks is Miss Cackle and confides in her. Mildred finds out it was really Agatha, after which she witnesses her in the kitchens trapping Miss Tapioca and putting a spell on the celebratory meal. The reason why Agatha had approached Mildred was because one of the ingredients of the spell is "tears of a young witch who has lost her dream" and during their conversation, Agatha had collected Mildred's tears on a hankerchief. When Mildred tries to warn the staff about Agatha, she is magically transported outside of the school grounds by Miss Hardbroom who says she has had enough of Mildred's lies. With the help of a magic frog by the pond her and Maud crash-landed into, she recreates the levitation spell she made in the practical exam and levitates herself back into the school through an open window, where she manages to prevent Miss Cackle eating the soup, announcing Agatha has put a spell on it. Agatha emerges from where she was hiding in the dining hall and says that she should be headmistress, and tells anyone who wants the school to be great again should stand up. Miss Drill does as she has already tried the soup with the spell in it - the spell was an obedience spell.
Agatha invokes section seven of the Witches Code - she and Miss Cackle have a magical duel, the loser of which must forfeit their powers. Agatha wins, after using Mildred as a hostage, and turns Miss Cackle into a snail. After Miss Hardbroom pointedly drops hints (in Midred's direction) about how staff and students accepted to the school are bound by the witch's code and can do nothing about Agatha now being in charge, Mildred, who is exempt from the code, prompts the cat to knock the soup laced with Agatha's total obedience spell over Agatha. Agatha is then under the influence of the total obedience spell and is temporarily loyal to Mildred who is the first person to give her orders, Mildred orders her to turn Miss Cackle back to normal and to forfeit the duel. Agatha's magical ability and knowledge are then confiscated. At the end, Mildred's mother Julie is magically transported into the school and, after talking it over with Mildred, she allows her accept the trial she is being offered at Cackle's Academy.
Miss Cackle: Here they come, the future of witchcraft.
Miss Hardbroom: The new term starts in six weeks, and THESE are our potential first formers.
Miss Cackle: I've got a good feeling about this year.
Miss Hardbroom: You said that last year.
Parent: Um, excuse me, Miss Hardbroom. Lucinda has problems with allergies and can't do potions. Who do I speak to about that?
Miss Hardbroom: Somebody from another school, perhaps?
Miss Cackle: Here. Take this.
Mildred: Is it magic?
Miss Cackle: Better. It's sugar.
Miss Hardbroom: Some of your papers were utterly abominable, and those were the better ones.
Agatha: Mother only gave you the school because you're 13 minutes older!
Ada: Those 13 minutes have saved this school from disaster.
Julie Hubble: So, you're magic, and all the teachers are magic, and the girls learn...magic?
Miss Hardbroom: I see where Mildred gets her quick wits, Mistress Hubble.
Julie Hubble: Prospectus, reading list, uniform requirements. Right. Ooh, what a lot of black!
Miss Hardbroom: Witches don't really do pink.
- It is unclear how Esmerelda Hallow and Miss Cackle first knew Mildred and Maud's names, given that Miss Hardbroom teleported them immediately to the tour after they crash-landed into the pond.
- Ethel should have noticed the pondweed that Mildred took was gone, because after Mildred took it, she was still taking some from the right scale.
- The school pond that Mildred and Maud crash into was heated to 23 degrees so the actresses didn’t get too cold during filming.