This is the third adventure of librarian Irene and her assistant Kai, a dragon prince with two forms, also working for the Library. The library itself is an interdimensional repository of books in all their versions from the many worlds that are linked to its portals. Alberich, ex-librarian gone bad, is threatening the Library with total destruction and Irene and Kai, together with Vale a Holmsian ‘great detective’ in a steampunky alternate London, and his Scotland Yard friend, Inspector Singh are trying to stop him with occasional help and hindrance from a couple of Fae met in previous books un the series. The events in Book 2 are taking their toll, on Vale and Kai in particular. Expect explosions, assassination attempts and general mayhem.