Page Turner: The princess and the burper: a fairy tale

Great excitement! The Secret of Moonacre, a film adapted from Elizabeth Goudge's 1946 children's classic, The Little White Horse, is out on 6 February, but I got invited to an early screening. A first glimpse at the cast list whetted my appetite: Tim Curry – what a splendid choice to play the 13-year-old heroine's gruff but adorable elderly uncle, Sir Benjamin Merryweather! So it was a shock to see the brooding Ioan Gruffudd barking: "Welcome to Moonacre Manor!" Uh-oh. Moonacre's in picturesque ruins, and he thinks he's Mr Rochester.

I know there have to be changes – and I can see why Goudge's Christianity has been stripped away, and why the evil Coq de Noir family, with their crest of a strutting rooster, have become Coeur de Noir – but I can't entirely applaud the makers' decision to gothicise the whole production. In the book, young Maria (surely Mar-eye-ah? here she's Mar-ee-ah) Merryweather arrives at her uncle's enchanting Devon castle, set in a huge park. Life is a delightful affair of huge feasts, gentle adventures, wise animals and eccentric characters. Only slowly does Maria realise that the valley is under threat, and only she, as the next Moon Princess, can set things right.

The book's Sir Benjamin is a benign buffer with white whiskers whose main concern in life is to set off his tummy in an array of fine waistcoats. Gruffudd stomps, sobs and rages, subsiding only to swig port while staring glumly out at his owl-haunted woods.

Perhaps the biggest disappointment is Juliet Stevenson's Miss Heliotrope, Maria's genteel but sickly governess. A tendency to dyspepsia has become a full-scale belching problem, which raised huge laughs from the children in the cinema, but is a sad travesty of the kindly and punctilious lady of the book.

However, there have been some ingenious reinterpretations and reshapings. Robin, Maria's young soulmate, has become the wicked son of Coq – sorry, Coeur de Noir (Curry, of course), roaming the forest with his gang in a sexy Clockwork Orange meets the Morris Men get-up. Natascha McElhone is a sweet, ditzy Loveday, Sir B's first love, now living rough in the forest in a cape borrowed from the Green Man. And Dakota Blue Richards is a wonderful choice for pert and perky Maria. The Secret of Moonacre will divide fans of the book, but that it's as good as it is, is something of a miracle.