• Every coin has two faces.
• Every war has two sides.
• One boy has to make the right choice.

The year is 1891 and London is at war. High up on the rooftops lives a ragtag band of orphans and spies – the Watchers – protectors of the city. But below the cobbled streets lurks the Legion, a ruthless gang of cut-throats and thieves, plotting to unleash the darkest forces of Hell. When a mysterious coin falls into his hands, cocky street urchin, Ben Kingdom, is flung into the midst of this ancient battle. The fate of the world rests with Ben, but which side will he choose? An army of angels... or the Claws of Evil?