At the centre of the Earth, in a world that no one knows exists, Will is in trouble. His enemy, the Styx, are close behind. They'll pursue him to the ends of the world – any world. Meanwhile Drake - with help from the unlikeliest of allies - is ...
preparing to fight the Styx from above. But will his daring plan bring him closer to victory ... or to certain death? The eagerly-anticipated fourth installment of the internationally bestselling Tunnels series.