Since the events of Chapter 8: The Tide Mice, the Tide Mice are still living with Hilda, though neither Hilda nor Johanna knows this. They made a nest under her bed. Then one day, when they look for useful stuff in her backpack, Hilda accidentally brings them along with her. As Hilda hurries to catch the bus, she collides with Gil Jones, a delivery man working for Jorts. This allows the mice to escape. After Hilda is gone, Gil sees the mice and feeds them some Jorts. The Mice thus attach themselves to him as their new host.
The mice begin to work their magic. Gil is summoned to the office of Wanda, the head of Distribution, and out of the blue he gets promoted to being her replacement since Wanda wants to go and see the world. This is the start of series of promotions, that eventually lead to Gil becoming the CEO of Jorts in the span of just 1 day. Jorts itself grows explosively from a mere snack company to a multinational. The Tide Mice however thrive in this new environment, and they rapidly multiply, with their young infecting the other employees at Jorts.
Meanwhile, Hilda, Frida and David are in the library for Frida’s witch studies. Then Kaisa tells them the Committee of Tree wants to see them right away. The committee informs the kids that the Tide Mice Hilda summoned are still at large, and causing trouble again.They want to throw Hilda into the juvenile void as a punishment, but Tildy shows up and prevents this. As Tildy and the committee argue, the kids sneak out of the library. Frida suggests they could capture the Tide Mice and bring them to Witches Tower so they can be banished for good. They search Hilda’s room, but find out the mice are no longer there. Then Hilda’s eyes begin to glow and smoke rises from her head, indicating that she is in the process of taking someone’s soul.
With time running out, the kids visit Kaisa at the Library. She shows them an article in The Oracle about Jorts sudden success, and Hilda recognizes the new CEO as Gil. Realizing that the Tide Mice are at Jorts, the kids and Kaisa go there. When they see how fast the mice have reproduced, they arm themselves with vacuum cleaners to capture every single one of them. As David, Kaisa and Frida take care of the new mice, Hilda makes her way to the CEO’s office to get the original 2 mice. She is able to separate them from Gil, but they flee into the ventilation ducts. Fortunately, Gil is able to lure them out with Jorts.
They all return to Witches Tower, where Tildy and the committee are still arguing. It is decided that Hilda won’t have to go to the void, but she is cursed with mouse whiskers for the rest of the day as a punishment for what she did. The witches unite to cast the disenchantment spell and banish the tide mice for good this time. The following day, Gil is back to being a delivery guy.
- Gil Jones
- Matilda Pilqvist
- The Committee of Three
- Head of Marketing of Jorts
Erik Ahlberg is mentioned but does not appear.
- This is the second episode where the Librarian plays a major role, the first being Chapter 3: The Witch
- Animation error: during the scene where David is questioning Frida in the library, he switches between wearing trousers and wearing his usual shorts.
- The vacuum cleaner with the smiling face that David uses to catch the Tide Mice is based on the real-life numatic's smiling Henry vacuum cleaners (also known as Henry Hoover).