A city under a spell - and the kids are the only ones who can free it.

Berrin lives in a futuristic world ruled by the evil Malig Tumora, who is known as 'The Great Father'. Like all the children in this city, Berrin has been raised without parents in a large dormitory that is constantly watched over by a gruesome collection of not-quite-humans called the Dfx.

In the storm-water drainage system beneath the city lives a group of children who have formed a resistance group to fight Malig Tumora; they call themselves the Rats. Berrin is recruited and learns that only children who are small enough to move around the pipe system can remain as Rats.

Trapped in the pipe system by his adult size is the Rats' founder, Ferdinand. He will only be free when the Rats succeed in rescuing all the adults who are under Malig Tumora's spell. But first they must defeat the security force of half-man, half-wolf creatures called Gadges, led by the very nasty Gadger Red.