- Episode Premiere: March 11, 2019.
After failing his history test, Will decides to make up to Miss Twilight by offering her a plate of cupcakes. He entrusts Bella to guard his Cupcakes while he goes to fetch a bow, in order to make the whole present complete.
While guarding the Cupcakes, Bella is enticed by the tasty dessert and decides to take a little bite for herself. She gets carried away and soon, Will's Cupcake present is half-eaten. Following Rose's advice, Bella runs to the cafeteria to get some replacement cupcakes but realizes the cafeteria is closed, causing her to clumsily drop the remaining cupcakes which fly all over the place and all over the floor.
Well, that's not good.
Rose then advises Bella to tell the truth, but Bella fears upsetting Will. Will appears with the bow and asks Bella where the cupcakes are. When Will starts getting upset with Bella for losing the Cupcakes, Rose steps in and says someone took the Cupcakes. Bella soon goes along with the lie, adding to it until it starts grabbing the attention of the other Fillies. With the lie slowly getting bigger and bigger right in front of them, Rose starts growing concerned. Bella assures her that the fillies will forget the whole thing come lunchtime. Battiwigs overhears the commotion and informs Wranglum of the monster.
The news of the "Cupcake-Stealing Monster" reaches Principal Sparkle, who announces cancellation of classes at the school and introduces a unique Monster-Fighting curriculum with a special advisory student. Bella is summoned to Sparkle's office to speak with the school faculty. Rose tells Bella its a great opportunity for her to tell the truth and put an end to the lie. But when arriving at the office, the teachers' overly zealous excitement over the monster story puts Bella back into a corner, and she doesn't tell them the truth.
Bella becomes famous and popular all around the school with a doting fanclub of Fillies wanting to meet her. Rose chases them away and scolds Bella for not telling the teachers. Bella responds that the whole thing was her fault to begin with. Rose explains that the whole story was to cover up for Bella's mistake eating Will's cupcakes, but the whole thing is no longer about Will, as now the entire school is involved. Rose expresses regret for starting the lie. Principal Sparkle then announces a red alert, and the entire school falls into a panicked hysteria. Meanwhile, Will upset over his lost Cupcakes and wondering how he'll bribe Miss Twilight now, devises a plan to set a trap to capture the monster. Wranglum and Battiwigs decide to leave the school to escape the monster.
Bella, while holding a Filly Self-Defense course is approached by Rose, who finally convinces her to meet with Will and tell him what happened. They come across a suspiciously large cupcake in the middle of the woods. The giant cupcake turns out to be the trap set by Will, which captures Bella. Stuck and with nowhere to run anymore, Bella and Rose finally confess to Will that the whole monster story was a cover up for Bella eating the cupcakes Will entrusted to her. Will forgives her and resets the trap, freeing Bella and the three friends head back to the school. Rose suggests Will study more to get a better grade from Miss Twilight instead of relying on Cupcakes as bribery.
Wranglum and Battiwigs, who overheard the Fillies are relieved that there is no monster. The duo accidentally stumble into Will's trap. It starts raining, causing Battiwigs to use Wranglum as an improvised umbrella, much to the villains' annoyance.
The Trope-Cake Mystery:
- Ask a Stupid Question...: After completely destroying Will's Cupcake Present, Bella stares at the empty plate and asks if Will would notice, Rose just gives her a funny look.
- "Fawlty Towers" Plot: Rose and Bella's little white lie about a monster becomes its own monster that spirals out of control.
- Hilarity Ensues: The school drops all sense of sanity once the monster story breaks out.
- Imagine Spot: Bella has a nightmare scenario about being expelled from the school after accidentally eating Will's Cupcakes.
- Insistent Terminology: Rose doesn't like calling the monster story a "lie". She'd prefer to call it a "fib".
- My God, What Have I Done?: Rose expresses deep regret for starting the monster story, now that the school is falling into a panic.
- Not So Above It All: Principal Sparkle and the rest of the school faculty even fall into the monster hysteria.
- What Could Possibly Go Wrong?: Bella when she decides to take a quick bite of Will's Cupcake, thinking no one would notice.
