They don't write them like this any more: most historical novels nowadays boast some kind of postmodern spin, but Elizabeth Palmer has simply spun an old-fashioned tale of wartime London, complete with an upstairs/downstairs cast, an illicit liaison in the stables, a homosexual heir, a mysterious governess and a generous helping of espionage. Hardly a tale of the unexpected, then, and you could almost draw up a list of the characters yourself - the drunken aristocrat, the elegant spy, the clever-but-penniless heroine - but she structures it cleverly, and as genre fiction goes, this is competent, even clever stuff.