"The Mystic Isles: The Great Pretender" is the one hundredth episode of the Disney Junior animated series Sofia the First. It premiered on November 3, 2017 and is the seventeenth episode in the fourth season.
At Royal Prep, the Royal Kids are on the way inside. Prisma and Twitch are nearby to obtain another of the Wicked Nine. Prisma pulls out the Locket of Vor and she asks the spirit where they can find the next object they seek. The spirit tells Prisma that it is in the office of the Fairy Headmistresses. The spirit also tells her it is well hidden, but she can find it. Suddenly, Sofia comes by with Princess Hildegard stating she heard that Royal Prep is having a guest teacher today. Prisma is annoyed that Sofia is one of the students at Royal Prep, but comforts herself with the knowledge that Sofia will be too busy in class to stop them. She and Twitch then head inside.
Meanwhile, Sofia and her classmates are in class. The guest teacher arrives and is revealed to be Merlin. Merlin tells the class that as they are about to enter their final semester at Royal Prep it is time for them to dream bigger dreams and shoot for higher skies. Because of this, they will do advanced Alchemy for the rest of the school year. Sofia is wowed by all the projects they will be working on from now on such as turning sawdust into gold dust. Prince Desmond tells her they will be harder than anything they have done before. Merlin concurs and tells the students that is why they will need animal helpers for the rest of the school year. After bringing in his animal helper Archimedes, Merlin explains that all top wizards have animal helpers to help with all sorts of useful things such as fetching ingredients, stirring ingredients, and opening scrolls. Hildegard asks if Lulu can be her helper, and Merlin tells her any animal will do as long as they are focused and hardworking. He then tells them their first advanced Alchemy project is due tomorrow, and their animal helpers will help make it in class. Sofia decides to pick Clover to be her helper and looks through her book to find a project for her and Clover to make.
Meanwhile, Prisma and Twitch enter the Three Good Fairies' office. Prisma pulls out the Locket and asks the spirit what the object is. The Spirit tells her it is the Spinning Wheel spindle that Princess Aurora pricked her finger on. After failing to find it, Prisma asks where it is. The spirit tells her it is inside a secret passageway that she must light a candle on the wall to open. Prisma tries to light the candle, but the candle keeps blowing itself out. The spirit reveals that Flora, Fauna, and Merriweather have put a protection spell on the passageway, and Prisma must break it in order to enter. Suddenly, Sofia and Fauna enter the office. Sofia has decided to make Dragon Fire for her project. Fauna is happy to help Sofia with her project and gives her the rarest ingredient that she needs to make it: Lightning Spark. Noticing Dragon Fire Ash on the candle, Prisma deduces that Dragon Fire is the key to undoing the protection charm and decides to use the Dragon Fire Sofia makes to do it.
Back at Enchancia Castle, Sofia finds Clover and asks him to be her animal helper. He accepts, but suddenly Sofia's other animal friends show up saying they want to be her animal helper. Sofia decides to hold tryouts to pick her animal helper. At the tryouts, Clover is the first in line. However, he soon has trouble due to not being able to tell one ingredient from the next. Wormwood shows up to check out "the next generation of animal helpers" and finds them all lacking. Clover is still having trouble to the point where his tryout fails. Clover wants to try again but Robin tells him he should let her and the others have a turn. Sofia agrees on the grounds that Alchemy Class is very important to her, but agrees to give him a second chance if he gets lessons from Wormwood first. Nearby, Prisma and Twitch, having followed Sofia back to her Castle, are watching everything. Prisma notes that Clover was terrible and suggests that Twitch be Sofia's animal helper. Twitch turns himself into a weasel and Prisma covers his diamond marking with a handkerchief. Twitch then goes up to the tryouts. In Cedric's Workshop, Wormwood tries to teach Clover a rhyme to help him identify the ingredients. Unfortunately, Clover has trouble remembering everything, and Wormwood finally gets so fed up that he kicks him out.
Meanwhile back at the tryouts, things are not going well. The only animal who does a good job is Twitch. Sofia notes that he is really good at this, and he would make a great animal helper. However, she still rejects him as she does not know him and wants one of her friends to be her helper. As Twitch leaves, Clover intercepts him and asks him for tips. Sensing an opportunity, Twitch turns himself into a chameleon and offers to coach him through his second tryout. Clover takes his turn again. Twitch blends in with his camouflage and tells Clover which ingredients is correct, making him successfully help Sofia make the Dragon Fire. Twitch tries to steal the Dragon Fire but fails as his chameleon form is not strong enough to carry it. After putting the Dragon Fire out, Sofia tells Clover he can be her helper, to his joy. Clover asks Twitch to help him the next day as well and Twitch says yes. After everyone leaves, Twitch tells Prisma he has a way to steal the Dragon Fire tomorrow.
The next day in Alchemy Class, the Princes and Princesses are doing their projects. When Sofia takes her turn, Twitch once again coaches Clover through it and they once again make Dragon Fire. Twitch then turns himself into a hawk and steals the Dragon Fire. Sofia and Clover give chase, and catch up in time to see Prisma use the Dragon Fire to open the secret passageway to steal the Wicked Nine object they are after. Having seen Twitch's diamond marking, Sofia realizes that Twitch is the same Strangeling who tried to steal the Falcon's Eye in Wei-Ling. Clover admits he had been cheating so he could be with Sofia. He does not think he is worthy of helping her anymore, but Sofia convinces him to try before Prisma gets the Spindle. At first Clover still forgets, but finally remembers the rhyme Wormwood taught him. Clover successfully helps Sofia make Dragon Fire on his own and they go after the pair. Meanwhile, Prisma and Twitch find an organ and, after playing it, open another passageway and get the Spindle. Sofia and Clover appear and, after a struggle, get the Spindle from them. Sofia sends Clover to give it to the Fairies. However, Prisma uses the Necessi-Key Twitch stole from Sofia to make a magical door to once again escape. Back in Alchemy Class, Merlin gives Sofia and Clover medals for their great work.
- Ariel Winter as Princess Sofia
- Wayne Brady as Clover
- Jim Cummings as Wormwood, Rex
- Megan Hilty as Prisma
- Jeff Bennett as Merlin, Twitch
- Paty Lombard as Vor
- Coco Grayson as Princess Hildegard
- Meghan Strange as Robin
- Ashley Eckstein as Mia
- Russi Taylor as Fauna
- Keith Ferguson as Praline
- Joshua Carlon as Prince Desmond
- Sofia wears her sorceress outfit for the fourth time in this episode. Followed by "Cedric's Apprentice", "The Enchanted Feast", and "Day of the Sorcerers".
- First time Merlin's assistant Archimedes appears.
- The secret passageway to the Spinning Wheel resembles the one from Sleeping Beauty, where Maleficent lured Aurora to where she got cursed.
- The Locket of Vor presented Maleficent's Staff as part of the Wicked Nine, so it's heavily suggested that the staff was transformed into the spinning wheel.
- Princess Hildegard's pet mink, Lulu makes her third appearance in the series, followed by "The Big Sleepover" and "Blue Ribbon Bunny".
- This is the last episode where Joshua Carlon voices Prince Desmond.
- Moral: Never cut corners to achieve success.