After Hilda and Frida come across a magical portal at the library, they must team up with the librarian in a race against time to find a missing book.
Song at the end: "Witch's Wand" by Sloan
Tropes:
- A Day in the Limelight: For Kaisa, the witch librarian.
- Bait-and-Switch:
- A lava monster appears outside Tildy's door, and Kaisa tells the girls to run while she handles it. We learn that the "monster" was Tildy's landscaper, and he wanted a friendly game of checkers.
- When Matilda Pilqvist states that one of the girls has the potential to become a witch, Frida and Hilda (and arguably the viewer) assume she is talking about Hilda. However, she meant Frida.
- Black-Hole Belly: Tildy's familiar, Cornelius, ate numerous objects that amount to a pile of garbage far larger than the cat-sized cloud creature that barfed it up.
- Bookcase Passage: Hilda and Frida go through several book-opened secret passages to get to the witch's tower.
- Call-Back: Hilda remembers Matilda Pilqvist from the events of "The Bird Parade".
- Chekhov's Gun: The sword and the plant that Hilda tried to fight become essential to subduing the creature from the void.
- Chekhov's Gunman: Matilda Pilqvist ends up being the lady that Hilda couldn't ring and run back in "The Bird Parade" and instead complimented her flowers.
- "Could Have Avoided This!" Plot: Tildy asks Kaisa why she didn't come earlier to get the book to avoid permanent exile. Kaisa confesses it's because she felt she wasn't good enough at magic and was disappointing her teacher. Tildy reassures her no, that she's awesome.
- Eldritch Abomination: The creature from the Void of No Return.
- Expecting Someone Taller: Both Hilda and Frida are surprised to learn that Matilda Pilqvist, the intimidating witch they learned about beforehand, is actually a sweet old lady.
- Fall of the House of Cards: The three witches of the Committee are building a card house when Matilda teleports herself, Hilda, Frida and Kaisa back to Witches Tower, which causes the house to collapse.
- Familiar: Various portraits of Witches and their familiars are seen in Witch Tower. When Frida becomes Matilda Pilqvist's new student, she predicts Hilda will become Frida’s familiar. Hilda is okay with that, because...
- Foreshadowing: During the exploration montage, Frida is the one who keeps helping them through the rooms thanks to her reasoning and knowledge. While Hilda is more action orientated and becomes disinterested when Kaisa tells her being a witch is more about book learning than doing magic. Matilda in the end tells Frida that she's the one with the potential to become a witch, not Hilda.
- Funny Background Event: The Skeleton Whisperer is a romance novel, judging by its cover.
- Girl's Night Out Episode: David is absent this episode, leaving Frida, Hilda and Kaisa to take care of the problem. Lampshaded by Hilda and Frida, who comment on David's absence.
- Human Sacrifice: It's revealed the witches didn't care about the due date; they were more worried about the monster in the void and it gets hungry easily.
- Karma Houdini: While the three witches face no consequences for bending the rules to sacrifice Kaisa and two innocent children, Tildy is giving them a Death Glare. She says she'll be training Frida, and no interference please.
- Killed Off for Real: When the creature emerges from the void, it first gets it’s tentacles on Lloyd. After the creature is subdued, Lloyd is not seen again, implying he was indeed killed.
- Living Lava: Eldrid, the lava golem that works as Matilda Pilqvist’s gardener, and whom Hilda and Frida mistake for the final monster they must fight to reach Matilda Pilqvist.
- Lovecraft Lite: The Void of No Return is a Lovecraftian Eldritch Abomination, but it can be fought by a skilled enough witch and is eventually subdued by getting another, equally dangerous creature to fight it.
- Mythology Gag: When Frida realizes they found the legendary Witches Tower, she mentions most people believe this tower to be in the Huldrawood. In the Graphic Novels, a map of Trolberg and surrounding area indeed depicts a structure named Witches Tower in the Huldrawood outside the city (it plays no role in any of the stories though).
- One-Steve Limit: Averted; one of the witches of the Committee is named Abigail, just like the Draugen captain from the previous episode.
- O.O.C. Is Serious Business: Hilda and Frida know something is wrong when they can’t find the librarian anywhere.
- Race Against the Clock: Kaisa has two hours left to find the book The Skeleton Whisperer before the 30 year check out time limit expires. If she fails, she will be sent to The Void of No Return.
- The Rest Shall Pass: Kaisa stays behind to fight Eldrid, so Hilda and Frida can get to Matilda Pilqvist. However, she knew the monster was not dangerous, and only did it so she wouldn't have to face Matilda.
- The Reveal: This episode reveals the librarian is a witch, and her name is Kaisa.
- Try to Fit That on a Business Card: Matilda Pilqvist is the enchanter of livelihoods, Grand Alchemist of the Dark Communion of Halgar, First Blood Sister of the order of the Black Candle, and another title that starts with “Tormentor of the”. It is implied she has even more titles.
- Secret Room: The secret room in the library that Hilda already discovered last season contains another secret room, which contains another, and another, and so on, until they lead to Witches Tower.
- Summon Bigger Fish: The girls eventually lure the plant creature they encountered earlier to the void to fight the Eldritch Abomination there.
- You Have GOT to Be Kidding Me!: Tildy's tone becomes incredulous when she asks if 'those three fuss buckets' really had them risk their lives in her labyrinth just to get an overdue library book.
