Ian Cawley from Rother Books in Battle in East Sussex said: "Very easy to read, very well written and unlike other spy novels, it's also incredibly funny."
Herron has a lively satirist’s eye and a comic sensibility that, in full flow, evokes early Tom Sharpe; these extravagant gifts are housed within a rock-solid plot involving a terrorist gang of unexpected origin acting out the moves of an MI5 playbook. The spectacular action set-pieces are expertly handled but they never overwhelm the gleeful cynicism of Herron’s true subject, which Slow Horses and Whitehall Masters alike understand intuitively as London Rule One: Cover your arse.
In October 2013, Mick Herron picked up the CWA Goldsboro Gold Dagger for his espionage thriller Dead Lions. Here on Crime Fiction Lover we agreed, and awarded the quirky espionage thriller five stars in our review... ... If anything Slow Horses is an even stronger book than Dead Lions, the War on Terror and its execution providing a deliciously ripe target for satire. The planning behind the abduction is all the more horrifying for its credibility. Herron captures perfectly the sense of panic and the consequences of decision-making made on the hoof as events spiral out of control.
The humour and satire make for a very different kind of read to the spy novels of say John LeCarre or Len Deighton and their topicality may eventually date them, but for now Herron’s Slough House series is ahead of the pack.