London Rules, Roddy Ho might say, is a game changer. On one level, that’s simply because it’s the first novel in the Mick Herron series that I’ve read before watching the TV adaptation. But the book is quite different from the previous novels. It is angry, about Britain and those in it who hold power, and dark, and bleak, and it is also extraordinarily funny. The ‘horses’ – MI5 agents in a kind of operational limbo due to various failures real or imagined – play a greater ensemble role than in previous novels, which have tended to place River Cartwright at their heart, but this should not be taken to mean that they have learned to work effectively or, even, together. I liked them less this time round, even while I was laughing at their antics.

Roddy Ho, a talented computer operator without any social skills or self-awareness, seems to have a girlfriend, which passes understanding. Then, an attempt is made on his life. The horses, one of whose number was gunned down in the previous novel, are taking all this seriously, though Head Horse Jackson Lamb declines to acknowledge the danger. Meanwhile, a horrible newspaper columnist is seeking to take down a popular and populist Muslim politician running for the West Midlands mayoralty, at the same time as her husband, a right-wing politician is trying to make things difficult for the prime minister. There’s blackmail, innuendo, racism and predatory behaviour, all of which goes to make the office politics of Second Desk Diana Taverner seem relatively benign in comparison (although it is not). 

Herron really dials upon the comedy in this instalment. There are spicy one-liners, running gags, like when Lamb sets himself up to say or do something utterly in character by claiming that it is not, or a game played by Louisa and Shirley which spills into inappropriate settings, or simple bathos at its best, such as when the self-styled ‘Rodster’ is on his way to take down the bad guys and falls flat on his face, or this, which is made possible through Herron giving voice to most of his main characters’ inner thoughts:

Neat little goatee and a baseball cap: originality plus style. Roderick Ho was the complete package, the way Brad Pitt used to be, before the unpleasantness.

Followed a few pages later by Shirley’s POV:

Ho looked, basically, like a dumb tourist who’d been ripped off twice already: once by someone selling hats, and a second time by someone giving away beards.

Herron is also great at finding fun in people’s ability to get stuck on irrelevancies. River and Coe discussing paint tin lids has me giggling, even though deep down I feel I should be making Herron work harder to entertain me.

Readers of and characters within the books have often wondered at Jackson Lamb’s ethics and motivation. They note that he is utterly loyal to his joes (and to others, such as Molly Doran) but wonder at his lack of affection for them. We await Lamb’s back story which we assume will spell some of this out in detail, but in London Rules we observe things a bit more clearly than in other novels. Jackson Lamb is an incredible spook. Operationally, he is far more advanced than anyone we’ve seen in mainline MI5. He claims to disbelieve Shirley’s warning that Ho might be in danger, but his joes’ safety remains his primary concern, not that he would state this. But it must be galling to put yourself on the line for such a dysfunctional bunch. Herron has always had us on their side until now, but the slow horses really are bad. They bicker like kids, they have no discipline, they are over-confident but generally inept. Their involvement really does make the situation worse. It is resolved by the involvement of other characters (including Lamb) working in their own self-interest and generally without involving others.

The phrase ‘London Rules’ implies cover-ups and although in previous novels the slow horses have been put in danger by the indifference or malign activities of others, this novel, for the first time in the series, sees lives in the ‘real world’ ruined because of the antics of our friends. We’d cry, if only we weren’t so busy laughing. And I don’t know what to make of that. Herron remains a master of ambiguity.

Slow Horses series 5, which is an adaptation of London Rules, is now streaming on Apple TV.

Episode 1: Bad Dates – episode reaction

Episode 2: Incommunicado – episode reaction

Episode 3: Tall Tales – episode reaction

Episode 4: Missiles – episode reaction

Episode 5: Circus – episode reaction

Episode 6: Scars – episode reaction

Our other Slow Horses/Slough House coverage