And Make Not Dreams Your Master — Richard Quarry

Why would a supposedly upright missionary die of an overdose of opium in a respectable Mission home? From upper-crust Mayfair parlors to opium dens down on the Limehouse docks, gaslight-era detective Nat Frayne investigates a tangled web of intrigue suggesting that China's bloody Teiping Rebellion has spread to London. Join him for a jaunt through murder, kidnapping, corruption and drug-smuggling in Victorian England.