An unnamed disaster has struck Earth and in a desperate attempt to ensure mankind's survival, a group of scientists build an underground city — a Noah's ark of sorts in which a human remnant can survive: the city of Ember.

They decide that Ember's inhabitants must remain underground for a period of 200 years — long enough for the effects of the disaster to have passed. To help the survivors return to the surface, a system is developed that will ease their passage to the outside world.

The key that would activate this system is locked in a box, which is equipped with a timer set to those 200 years. The box and its precious contents are entrusted to the first mayor of Ember, to be handed from mayor to mayor until the right time comes.

But after several decades, one of these mayors dies without the secret of the box being revealed to a successor, and the box is stored away in the back of a room, its existence wiped from the collective memory of Ember.

After two centuries the box silently clicks open in its hiding place, without anyone being aware of it — and its secret remains hidden for many more decades. That is, until two teenagers unwittingly come across the box and begin to unravel its secret as Ember's gigantic generator begins to fail, threatening the city's inhabitants.

The imagination quivers in anticipation with a premise like this. But unfortunately it fails to live up to the promise.

The excitement and imagination do flare up every now and then, but never reach the anticipated heights. Which is a devastating pity, because so much could have been done with a story like this.

But the puzzles get solved too quickly; the answers revealed too willingly. What excitement the movie delivers, is tied to side-shows that detract from the elements that should have been focused on. The result is a barely breathing slump from one end to another.

Even the climatic chase through tunnels is too reminiscent of 'The Goonies' to be much fun, failing to live up to the child-like wonder that the '80s classic engendered.

This is not to say that 'City of Ember' is a complete waste of a Friday night, just that reading Jeanne Duprau's book upon which it is based would probably be a much more rewarding experience than this cinematic show-and-tell.

Bonus:
Behind the scenes featurettes and a "making of scene" could prove to be interesting but will probably just detract further from the little wonder the film did garner.