I would quite comfortably say that this is the worst book I have read in about five years.
The writing is laboured and heavy-handed; the characters are two-dimensional, and the dialogue is almost physically painful to read. The author has chosen to make his lead character a magician, and yet has clearly done no research whatsoever into the history of magic (for instance: the story is set quite clearly in 1853, and a reference is made to a magic trick first performed in the 1920s). The sub-editing is dismal (at one point there is a reference to saltwater, which switches some ten pages later to rainwater), and at one point a paragraph is repeated verbatim on two consecutive pages, interrupting a sentence half-way at one point (though this may be a printer's error).
Add to this unappetising mix a couple of plot points lifted directly from Boris Akunin (to whom the publishers had the audacity to compare this doggerel favourably), woeful anachronisms, contradictory character motivation, an apparent inability to read a map of London, a singularly unlikeable hero, a macguffin that makes absolutely no sense, and you have a thoroughly disappointing reading experience. Save yourselves! Read virtually anything else instead!