Clawdeen finds that balancing school with her new role as Were-Ruler is way more challenging than she thought; as she faces her first big task as Were-Ruler, Clawdeen makes a decision that will shake up the were-world.
When Draculaura learns that Skelita is also practicing witchcraft, she eagerly shows Skelita the "right way" to be a witch; Clawd wants to spend a monster holiday, Friday the 13th, with Selena, but a time loop interferes with his plans.
Wanting to gain more followers, Cleo makes a deal with an ancient mirror that tries to take over her life; Clawd and Draculaura fiercely compete to see who can scare Mrs. O'Shriek first and restore her lost banshee scream.
The Boo Crew vacations to the Bermuda Triangle while Dracula considers which Were-Ruler to endorse; Clawdeen investigates a destroyed sandcastle that could change the course of the election and discovers surprises on the island.
When Ghoulia's anxiety manifests as a monster, she hurries to get rid of it before an appointment with the school counselor; worried for Frankie's safety, the Drs. Stein reprogram Frankie's latest robot invention to protect them at all costs.
Convinced that Deuce is lonely, Lagoona and Heath set him up for an ultra-romantic Heartbeast Night to lift his spirits; Toralei attempts to mentor a rowdy young werecat, but she soon realizes that she may be teaching her Little Paw the wrong lesson.
When Ghoulma Vondergeist announces that she's retiring to Sarasotaaagh, Spectra sabotages their family haunt to get her to stay; inspired by his comic books, Gil takes on a superhero persona at school, but the power quickly goes to his head.
Deuce wants to show off his pet rat Perseus at the Pet Scare, but when the rat won't participate, he finds a destructive replacement; jealous of Jinafire, Heath tries to outdo her climate activism with a superior Climate Science project.
Clawdeen organizes a "Get Out to Vote" concert with Catty Noir, but a shapeshifter threatens to ruin the event; stuck in an alternate dimension, Clawdeen and Romulus must work together to get back to Monster High before the concert.
After Draculaura accidentally offends the Codex and causes him to run away, she resorts to witchcraft to fix their friendship; Lagoona must work up the courage to be honest with her ghostly ex-boyfriend when he comes back into her life to haunt her.
Wanting to be more of a "boss monster" like Nefera, Venus overworks herself and gets in over her head by refusing help; Bunny Earickson searches for a special pollinating bat in order to locate a companion plant for a wilting Venus.
As Head Haunter of the Monster Fest, Frankie frets over the best way to run the festival and considers handing the reins over to Hades; when Hades sponsors the Monster Fest, monsters start to disappear, leading Frankie to investigate.
Frankie, Phoenix, and Heath search Hades' Underworld factory for their missing friends and discover a surprising culprit; the Boo Crew must "weave their own webs" and battle a foe to save the festival.
On the night before the election, Clawdeen confronts the shapeshifter and realizes that Headmistress Bloodgood is in danger. The Boo Crew must unite to expose the shapeshifter's true identity and ensure that the election goes off without a hitch.
