Rose and the Magician's Mask, by Holly Webb-- which was much nicer to read. My questions were all internal to the story, of a wondering, speculative kind, and I never once was kicked out of the narrative by infelicities.
Rose and the Magician's Mask is the third book about Rose, an orphan girl with magical powers in an alternate 19th-century England. The first, Rose, was published here in the US in 2013 (and was shortlisted for the Cybils), the second, Rose and the Lost Princess, comes out here this April. Some of us couldn't wait, and me and my boys went and ordered all four Rose books and the first book in the spin-off series about Lily from the UK.
In any event, in Rose and the Magician's Mask, a powerful mask is stolen by a magic-wielding antagonist, and taken off to Venice...a city steeped in magic. And Rose and her cohert, including Gus the cat, set off to find the mask and thwart the antagonist. It is a lovely magical Venice, full of creepiness and mysetery. And though I would have liked slightly more forward progress with Rose's magical education, and slightly brisker character development (both are happening, but not very fast!) it was, all in all, satisfying.
If you have an eight to ten year old reader of fantasy around, do try Rose (and its sequels, as they come out) on him or her. The US covers are happily more gender neutral than the very girl oriented UK ones; none of the kids in my ten year old's class batted an eyelash at the cover of Rose, but apparently some boys asked my son why he was reading this one (not that he cared).