Celebrated sci-fi writer Neil Gaiman, who created the Sandman series, scripted this visually adventurous fantasy. Helena (Stephanie Leonidas) is a 15-year-old girl who has spent nearly her entire life on the road, traveling with her parents Joanne and Morris (Gina McKee and Rob Brydon), who make a living as circus performers. One night, Helena wishes for a quieter and more stable life, only to panic when her mother falls seriously ill, ending up in the hospital. Afraid she's caused her mother's illness, Helena slips into an alternate reality known as the Dark Lands, where nearly everything behaves differently and all is ruled by the Queen of Light and the Prime Minister (also played by McKee and Brydon). As it happens, the Queen of Shadows' daughter, who bears an uncanny resemblance to Helena, has gone missing; the Queen of Light has fallen unconscious as a result; and both queens' minders are looking for the child. As Helena struggles to make her way back to her own world to help her own mother, she discovers the Queen of Shadows' daughter has taken her place. Helena is aided in her journey by a gifted juggler named Valentine (Jason Barry), and together they seek to access a magic charm which will return everyone to the land where they belong. MirrorMask was produced by the Jim Henson Company, with most of the sets and many of the characters created using digital-effects technology.
by Mark Deming synopsis