Clown Town is the ninth Slough House novel by Mick Herron. Still on medical leave after Bad Actors, River Cartwright pokes around his late grandfather’s library and discovers a supposedly “missing” book that may hide state secrets from the Troubles era. At MI5 headquarters, First Desk Diana Taverner faces blackmail over that same covert operation and looks to Slough House’s disgraced spies as expendable assets. Jackson Lamb warns his “slow horses” to stay seated—knowing they won’t—and vows a reckoning if any of his misfits fail to return.