City of Ember (PG) Directed by Gil Kenan. Starring Saoirse Ronan, Harry Treadaway, Bill Murray, Tim Robbins, Martin Landau, Mackenzie Crook. 90 mins Three star rating It s an interesting move to open a children s film with the line: On the day the world

City of Ember (PG)

Directed by Gil Kenan. Starring Saoirse Ronan, Harry Treadaway, Bill Murray, Tim Robbins, Martin Landau, Mackenzie Crook. 90 mins

Three star rating

It's an interesting move to open a children's film with the line: "On the day the world ended." Just as The Boy In The Striped Pyjamas works on the principle that they are never too young to open up an awareness of intolerance and genocide, so City of Ember gives young minds a solid grounding in how power corrupts and mankind's capacity for complacency.

Jeanne DuPrau's book on which the film is based was originally a prime piece of Cold War nuclear paranoia, but its premise now works equally well as an environmental parable.

With the Earth facing some unspecified global catastrophe, the remains of mankind are sent down into an underground city with instructions on how to return to the surface once 200 years had passed.

Unfortunately the message gets lost and the generator that sustains life is faltering, frequently plunging the city into darkness and is on the verge of collapse.

Only two youngsters, Lina (Ronan from Atonement) and Doon (Treadaway from Control), seem to have gumption to ask questions, challenge authority and save the city.

The film's main asset in the City itself, an enormous self-contained set located in a Northern Ireland sound stage which looks like Zion from the Matrix films remade in the style of Rachel Whiteread's recent installation of 200 doll's houses at the Haywood Gallery.

There's something rather old-fashioned about the film's design with lots of Heath Robinson-style creations. With all the pipes and air locks and the sense of claustrophobia, at times the film resembles a giant submarine movie.

Scripted by Tim Burton's regular writer Caroline Thompson, this is certainly an odd little children movie and at times damn right scary.

But the main problem is not so much the darkness as a certain drabness. Under Kenan's direction the movie never really enchants and the sometimes clumsy editing suggests a film that has been cut back from its original length.

Bill Murray has a few great creepy moments as the Mayor of Ember City but mostly a good cast (Toby Jones, Marianne Jean-Baptiste, Liz Smith and Mary Kay Place also appear) doesn't get enough to do in what is a bold but not entirely successful enterprise.