Of course we were pining for our next hit of Jackson Lamb ruling over his band of misfits at Slough House, but no, “The Secret Hours” is billed as a standalone spy thriller. That is not exactly true, even though The Secret Hours does not mention the Slow Horses, for this novel is a hefty (nearly 400 pages) “origins of” backstory, dressed up within a startlingly up-to-date internal investigation by the secret service. After an opening action scene that is the most pulse-pounding bravura stretch of writing I have read for years, the novel devolves into a wishy-washy inquiry run by two hapless desk jockeys, saturated with the author’s trademark wisecrack, cynical take on the modern world, into which explodes ancient spy tales from 1994 Berlin (Berlin being, of course, the heart of all spy thrillers, ever since the advent of George Smiley). Herron’s plotting is as devious and brilliant as any he has deployed and the spook atmospherics are superb. From the start, I sensed a deep homage to some of John Le Carre’s classics, the ones where innocents and not-so-innocents intertwine into a tapestry of grand beauty, horror, and yes, love. All of the above words add up to a verdict that surprised when it dawned on me: The Secret Hours is Mick Herron’s masterpiece, a grand drama written so well it will survive the eons. It is a compulsory read but, I regret to say, one that should properly follow the eight Slough House novels (and please, don’t omit the four interposing novellas!). Grace yourself with those books and The Secret Hours, and you too shall be redeemed.