Croix gives a lesson in Modern Magic to the students in the close open, and her Ley Line Router delights all but Diana. Curious about the new teacher, Diana goes to the Luna Nova Library to examine her background in the graduation registers. Ursula approaches Diana, who remarks on what she has learned. Ursula provides her own personal feedback about Professor Croix, which makes Diana speculate the two were close when they went to school together. Ursula denies this and defensively claims that what she said was just secondhand knowledge, before abruptly leaving with the remark that she is too busy as a "regular" teacher. Suspicious of this reaction, Diana searches the registers for Ursula.
At the Cafeteria, Akko waxes about how great the new teacher is. Lotte finds a profile of Croix in the newspaper detailing the professor's accomplishments and revealing that she went to school when Chariot was there. Akko excitedly speculates that they were rivals, which is denied by Professor Finnelan who has overheard the conversation. Croix was a hardworking student who got great marks in school and showed promise, while Chariot neglected her studies and wasted her natural talent on a silly entertainment show, becoming an embarassment to witches. Akko slips away to visit Croix and ask her about Chariot. She is elated when Croix speaks highly of her, and reveals her intentions to find Chariot. Croix offers to help locate Chariot with her Magitronics if Akko can provide something connected to her. Akko promises to bring Chariot's Staff, the Shiny Rod, to Croix's lab in the New Moon Tower for analysis.
Meanwhile, Ursula is occupied with concerns about Croix's intentions in returning to Luna Nova, knowing that her target is the revived Claiomh Solais. She goes to check up on Akko but is told by Lotte that she had gone to the New Moon Tower with the Shiny Rod at Croix's request. She immediately realizes that Akko is in danger.
A Magitronic robot guides Akko up the New Moon Tower to Croix's lab. Croix welcomes her begins and begins to analyze the Shiny Rod. She explains that it is activated by spiritual energy and asks Akko if it has ever reacted to her emotions, which she confirms. Without giving her a chance to respond, Croix then proceeds to scan her emotions and memories to find out how and why she can activate the Shiny Rod. As she watches the scan play across her wall of monitors, she is alerted to a still of Ursula captured by a security camera.
Finding that Chariot has arrived at the Tower, Croix unleashes its considerable defenses against her. She is surprised at the ease Chariot surpasses them in her ascent up the tower, expecting her power to have waned considerably after hiding it for a decade. It is revealed that she became bitter enemies with Croix, who sought to use the world reconstruction magic for her own agenda. Chariot swears to protect Akko against Croix's evil machinations.
Akko is confused to awaken in Ursula's room. Ursula tells her about the Cosmic Tree Yggdrasil, the source of all magic. Over time the tree's presence in the world faded, leaving only its branches (leylines). The seed of the tree and the core all creation, the Grand Triskellion, was sealed away within the sacred Arcturus Forest by the founders of Luna Nova to ensure its preservation. Ursula reveals that Akko has already activated three of the seven long-lost magic words which comprise the seal. Six of the words are known, but they cannot be merely taught, a witch must believe in them with complete conviction in their heart. Akko surmises that Chariot has disappeared because she is looking for the Seventh. Believing that she will finally meet Chariot again if she succeeds, (Chariot has not told her secret yet) Akko passionately declares her intentions to finish the unlocking of all the seven words.
Order of appearances
- The appearance of the Shooting Star in the newspaper is a running gag.
- When Diana is reading Croix's profile in the student album, the name Salem Saberhagen can be seen to the left.
- Chariot loses her hat and hair tie and discards her skirt and glasses in the process of her ascent to Croix's lab, but she has them when Akko awakens.
- Croix leaves her lab while Chariot is still inside.
- When Croix was probing Akko's mind, there are flashes between old scenes of Chariot's magic show interspaced with a new one about Akko as a child trying to ride a broom.
- The advance cut for this episode was the first to not end in Akko saying "So thrilling and exciting! (ドッキドキのワックワク！ Dokkidoki no wakkuwaku! )" Instead, the quotation is one of Chariot's from this episode, "What have you done to Akko?!"
- Episode 19's ends in Diana saying "Goodbye, Luna Nova. (さようならルーナノヴァ。 Sayonara, Luna Nova. )" Previews for episodes 20-22 similarly end in such a way.
- Posters in the Academy Cafeteria promote the Wild Hunt, foreshadowing "Sky War Stanship".