|The Blue Rainbow|
|Original airdate||March 12, 2019|
|Previous||The Cupcake Mystery|
|Next||Wranglum in Disguise|
The Ukrainian dub's synopsis
(taken from the official Ukrainian page for 'Filly Funtasia' and translated to English)
Today is one of the most important days in the history of Funtasia. Once in a three thousand of years a real miracle happens there: you can see a blue rainbow up over the hills - it's a unique rainbow which is created solely using the shades of blue colour. But what's important the most is that when the blue rainbow will hit the hills of Funtasia, a powerful blue crystal will appear. And to get the crystal you'll have to arrive there at the exact time when the rainbow appears the most close to the hills. But will Zack and his assistant Rose be able to obtain the crystal?
There's a russian language version as well. Its text is almost the same, except for the word 'three hundred' being an informal part of the language.
In Twilight's class, students learn from her apprentice, Zack, about a blue rainbow that appears once every 300 years and creates a crystal upon touching Funtasia's hills. Zack asks for a volunteer to find the crystal with him, and Rose, Bella, and Lynn (evidently finding Zack attractive) are all eager to help, but Rose is the quickest to lift her hoof.
After class, Rose gets called to Principal Sparkle's office, where Sparkle asks her to look after Fabian, a new student. Rose shows Fabian around the school, but he's very clumsy, not used to his new school-issued crystal mirror, and his main interest is geology (rocks). Rose's patience runs thin as Fabian repeatedly causes problems. Meanwhile, Wranglum is also interested in the blue rainbow's crystal, needing its power to help his plans of escape and destruction.
Rose sees the blue rainbow through the window, but is still looking after Fabian. He wishes to visit the academy's basement (Wranglum's lair) as its walls are made from a type of rock he's particularly fond of. Rose takes him there, but then lets slip that she wanted to go and help Zack. Fabian tells her that he's happy to stay in the basement and practice magic while she goes to help Zack, and Rose happily agrees. Shortly after Rose leaves, Fabian finds the magic portal to the forest that Wranglum has opened and falls through into the clearing with Wranglum, losing his glasses.
In the forest, Rose and Zack find the rainbow and obtain the crystal. Battiwigs finds them shortly after and is intent on getting the crystal back for his master.
The extremely short-sighted Fabian mistakes Wranglum for his mirror and calls Rose asking for help. Seeing that Fabian is near a cliff, Rose insists that to Zack that he needs rescuing. The pair fall into a pit trap that Battiwigs constructed, and Zack drops the crystal and hurts one of his wings. Battiwigs returns to Wranglum with the crystal just as as Fabian accidentally drops Wranglum off the cliff. Dropping the crystal, Battiwigs swoops after Wranglum and manages to save him, though the pair are attacked by an owl.
Down in the pit, Rose calls Fabian for help. Fabian has now found his glasses, his real mirror and the blue crystal. Rose and Zack create a pillar of light, which Fabian follows to find them, though he, too, falls down the pit. Together, the trio walk through the large caves until they reach what appears to be a dead end. Zack and Rose are stumped, but Fabian realises from examining the rocks that the wall is thin, and the three get free. They go to Sparkle's office and Fabian covers for Rose, saying that he has had an enjoyable but uneventful day. Sparkle is happy, and compliments Rose for having looked after him, and Zack for successfully getting the crystal. Sparkle adds that she couldn't imagine what would have happened if such a powerful crystal had been taken by the wrong person.
Meanwhile, Battiwigs and Wranglum have returned home to find Wranglum's lair swarming with forest critters, including the aggressive owl from earlier.
- This is the first episode Zack and Fabian appear in for the series.
- This episode's title was first given as The Missing Student.
- This episode was first given as the third episode of the series, but one of the concept art pictures with the scene where Fabian, Rose and Cedric are searching for the exit from the cave has a text suggesting it could be the sixth episode.
- The scene where Rose, Zack, and Fabian walk through the caves was used for the October 2014 trailer, starting with Fabian falling into the pit and ending with the group reaching a dead end.
- The episode was nominated at the 'Asia-Pacific Film Festival', but lost the place to another nominee, 'Funtamental'. Funtasia Daily wrote an article about the event.
- Ukrainian: 'Синя райдуга
- Russian (as seen on the site of PlusPlus): Синяя радуга;
- Serbian: Plava duga;
- Czech: Modrá duha;
- ↑ (In ukrainian) "Сьогодні надзвичайно важливий день в історії Фантазії. Раз на триста років тут стається справжнє диво: над пагорбами можна побачити синю райдугу – унікальну райдугу, що складається лише з синіх відтінків. А головне, коли синя райдуга торкнеться пагорбів Фантазії, то утвориться могутній синій кристал. Щоб його дістати, треба бути на місці саме тоді, коли райдуга торкнеться пагорбів. Чи вдасться Заку та його помічниці Роуз його дістати? " 
- ↑ (In russian) "Сегодня очень важный день в истории Фантазии. Раз в триста лет здесь происходит настоящее чудо: над холмами можно увидеть синюю радугу – уникальную радугу, состоящую только из синих оттенков. А главное, когда синяя радуга коснется холмов Фантазии, то образуется мощный синий кристалл. Чтобы его получить, надо быть на месте именно тогда, когда радуга коснется холмов. Удастся ли Заку и его помощнице Роуз его достать? "