A companion piece to Herron's acclaimed Slough House series, The Secret Hours is both an entertaining piece of espionage fiction and a profound and acerbic look at Britain’s clandestine service. As he delves into this institution, Herron exposes its vulnerability to the machinations of politics, using this as the starting point for moral and philosophical questions about the nature of humanity, and, not incidentally, proving himself the heir to the late, great John le Carré.