The Extraordinary & Unusual Adventures of Horatio Lyle - Catherine Webb

In Victorian London at the height of the industrial revolution, Horatio Lyle is a former Special Constable with a passion for science and invention. He's also an occasional, but reluctant, sleuth. The truth is that he'd rather be in his lab tinkering with dangerous chemicals and odd machinery than running around the cobbled streets of London trying to track down stolen goods. But when Her Majesty's Government calls, Horatio swaps his microscope for a magnifying glass, fills his pockets with things that explode and sallies forth to unravel a mystery of a singularly extraordinary nature.

Thrown together with a reformed (i.e. 'caught') pickpocket called Tess, and a rebellious (within reason) young gentleman called Thomas, Lyle and his faithful hound, Tate, find themselves pursuing an ancient Chinese plate, a conspiracy that reaches to the highest levels of polite society and a dangerous enemy who may not even be human. Solving the crime will be hard enough - surviving would be a bonus...