After Aubrey narrowly escapes the worst fate he can imagine, he realises there is only one thing to do: he must confront his nemesis. With George and Caroline at his side, he travels to Holmland - the home of Dr Tremaine and the heart of hostile territory - only to face magical conundrums, near-death experiences, ghosts, brigands and enemies on their own ground. Fisherberg is a city on a knife edge. Can Aubrey solve its mysteries before Dr Tremaine’s warmongering machinations tip the world into chaos?