Skull, the Shadow, and a few of the rat army escaped into Perodia, and now Tag and the other defenders must locate them, and also find their friend, Bod, who is still trapped in the Underland with the rest of the rat army.

"The Concord has been broken, and a war of magic engulfs the world. In France, the brilliant young battle-mage Napoleon Bonaparte has summoned a kraken from the depths, and under his command the Army of the Dead have all but conquered Europe. Britain fights back, protected by the gulf of the channel and powerful fire-magic, but Wilberforce's own battle to bring about free magic and abolition has met a dead end in the face of an increasingly fearful...