The Secret Hours

Mick Herron

Baskerville £22

Herron steps away from his Slow Horses, but not the world of espionage, for this thriller. A retired agent suffers a break-in just as a committee investigates Secret Service wrongdoing. There are no coincidences in this world and the trail gradually leads back 30 years to Berlin and an operation that went wrong, offering a revealing sidelight into the pre-history of Slough House. More sombre than usual but still compelling.