Get ready for more brilliant page-turning fantasy from master Garth Nix. On the fourth day there was war! Pick up with Arthur Penhaligon as his Keys to the Kingdom adventures continue in the mysterious House. Following their adventures in the Border Sea Arthur & Leaf head for home. But only Leaf gets through the Front Door. Arthur is blocked because someone -- or something -- has assumed his identity & is taking over his life. Before Arthur can take action he is drafted by Sir Thursday & forced to join the Glorious Army of the Architect. The Army has its headquarters in the Great Maze a defensive area of the House. Half of the Maze has already been dissolved by Nothing & hordes of Nithlings emerge regularly to attack the rest. If the Nithling invasion can overcome the Army & the Great Maze the House will be lost & the whole universe with it. While Leaf tries to banish Arthur's doppelganger on earth Arthur must survive his basic training avoid getting posted to the Front & work out how he can free Part Four of the Will & gain the Fourth Key from Sir Thursday. If the latest strongest & most dangerous Nithling offensive doesn't break through first!