[5][6] Produced by Ánima Estudios, Prime Focus World, and GFM Animation, the film features the voices of Toby Kebbell, Lily Collins, and Ian McShane.

The Grin casts a spell to make people happy, but the magic deprives the subjects of their morality, resulting in instant pandemonium.

On Earth, Mary owns an amusement park that resembles Groovingham and has a grandson named Terry Dexter.

Meanwhile, the Grump, who was captured at some point for his purported crime, escapes from prison alongside his diminutive henchmen called the Grumpies and enacts vengeance upon the king.

Princess Dawn manages to escape the gloom by being hidden in a chamber beneath her bed by her servants while her pet, Bip, leaves Groovingham to seek help from an outsider.

When his minions inform the Grump that Dawn had escaped the gloom, he returns to the castle where Terry recognizes him as the Grin from his grandmother's story.

After being chased by the Grumpies through the castle's interior, Terry and Dawn reach the map room where they met a bird named G. P. Sparrow, who agrees to navigate them to the Oracle who knows how to lift the Grin's curse.

Princess Dawn and Terry learn from the Oracle that they need a magical key from the Cave of Whispering Orchards to restore happiness in Groovingham, which the Grump overhears.

As Terry and the balloon people fight back, Dawn causes Dingo to sneeze, sending the Grump mounted on him flying away.

With repairs finished on the blimp, the Grump lands on a nearby branch protruding from a cliff and casts the gloom spell on Dawn before plummeting.

Seeking help from an alchemist to treat Dawn's condition, Terry learns that a kiss can break the curse afflicted upon her before sunset; otherwise, the spell will be permanent.

However, after going through with it, Terry admits that he lacks feelings for Dawn since he has only known her for a day and that he wants to return home, upsetting the princess who dismisses him.

Terry reopens Groovingland, where he introduces Dawn to his parents and employs the Grump and the other characters from Groovingham as attractions.

This hugely talented voice cast, alongside the beautiful animation delivered by the artists of Ánima [Estudios] and Prime Focus, has brought these fantastic characters to life in ways we couldn't have imagined.

We are sure that the audiences will love McShane's grouchy character, Lily's adorable princess and Toby's cool hero".