Jess trains all summer so he can win a race at school, but then he is beaten by new girl Leslie. However they soon become fast friends. Leslie loves to tell fantastical stories while Jess loves to draw but has never shared his talent with anyone. Together they create the world of Terabithia, a magical place they can reach by a rope-swing across the stream in the woods. There they rule the kingdom, fight the Dark Master and his creatures and plot against the school bullies. Thanks to their friendship, Jess's life changes forever.

There are lots of thrilling mini adventures in their fantasy world with hints of danger and lots of energy. Csupo makes the forest quite spooky at times, using mist, sudden noises and half-glimpsed figures to shiver the spine. There is a surprising twist about three-quarters of the way through the story that will blindside you if you don't know the book it is based on and it's certainly one I'd failed to spot. It leads to an abrupt but appropriate shift in tone that deals sensitively but straightforwardly with a delicate subject. It turns the film on its head and bringing greater emotional depth to the narrative, not bad considering there's only ninety-five minutes in which to do it.

The screenplay by Jeff Stockwell and David Paterson tunes in to what it is like to be an outsider. So we see Jess trying desperately to prove himself to his peers in order to be accepted by them. But in Leslie we have a character that doesn't care about others' opinions and shows that it is acceptable to be yourself and not go with the flow. Their relationship grows slowly. His initial antipathy towards her is understandable and it's only through sheer force of personality that she wins him over. Many of the other players are stock characters; Jess' authoritarian father, Leslie's bohemian parents, mean teachers, misunderstood bullies and a youthful music teacher who is bit different from all the rest. But they work in the context of the narrative. The central themes are universal; using your imagination to escape everyday troubles like mean teachers, bullies and strict parents. The pacing is also very tight - there's very little fat on the movie. Once we've been introduced to the characters and their contrasting ways of life, it's full pelt into the story and a series of mini adventures that will keep the kids entertained. There are also some bigger issues that I can't talk about without ruining the story, which are dealt with in a sensitive but unsentimental manner.

Anna-Sophia Robb is steadily growing as an actress. As Leslie she has something of a devil-may-care attitude. She comes across as a young girl entirely at home with herself, so she isn't afraid to be different to everybody else. She carries off Leslie's punky style with aplomb and convinces as a natural storyteller. As with Hutcherson, she interacts well with the imaginary aspects of the film and you feel like she's really seeing everything she's imagining. And there is palpable warmth between the two child leads.

The original music by Aaron Zigman is a lot of fun. He uses traditional orchestral and electronic instruments to get the desired effect. So there are combinations of piano, synths, strings, electric guitar and choruses that introduce the film, setting a high energy pace. There are lots of string arrangements that affect the mood of the accompanying scenes. They can be playful, or thrumming with energy as in the race where they are married with synthesizers. For the forest where the kids' imaginations play out, Zigman employs magic-tinged brass and twinkling chimes and ethereal choruses for the rope swing that leads to it. There are epic orchestral themes for Terabithia itself and hectic 50s B-movie horror themes when Jess and Leslie are under attack. In more emotional moments, sad solo piano is used to heighten the mood.