When a bomb wrecks a train in one of London’s rail stations, the MI5 operative deemed responsible, River Cartwright, finds himself sent to Slough House. It’s where all MI5 agents who fail spectacularly go. Slough House has only one purpose: to drive the agency’s “slow horses” to resign. Only Jackson Lamb, the overweight, overbearing head of Slough House, cares to be there—after all, it’s his kingdom.
Things change, however, when British nationalists kidnap a Pakistani student and threaten to cut off his head live on the Internet. All of MI5 is on alert, including the Slough House misfits, who are dropped into the thick of it when it is discovered that one of their own is involved. Soon, Lamb and his agents are not only scrambling to find the kidnap victim, but dodging their own fellow agents.
The narrative is laced with the sort of dry, cynical sarcasm you’d expect in a story about people whose careers are finished. In Herron’s take on the spy thriller, parallels are drawn to Ian Fleming’s novels about the better-known and more glamorous MI6 and James Bond. The message here? MI5 is decidedly duller and more political than its sister agency, riddled by corruption and inefficiency. Herron’s MI5 lives in more fear of bad press and politicians than terrorists. Though the humor is subtle, Slow Horses’ verdict on Britain’s security service is blunt as hell.