The thing you need to know about the Slow Horses of Slough House is that they aren’t slow, or horses, or in a house or in Slough. Nor are they there by choice. They are spies who are, largely, in disgrace. They have made mistakes, through incompetence or by earning enmity, or by allowing themselves to be a pawn in another game, or by personality, or simply by being tired. But they make an effective, if ramshackle, team, perhaps taking the characteristics of their effective, if ramshackle leader. 

The Slough House series of spy thrillers by Mick Herron has been around since 2010, but it has won a new audience because of Slow Horses, the smash hit serialisation on Apple TV. Having watched the first three series (four is in the can, five is being filmed), I know I’m not alone in checking out the novels in an attempt to get ahead. 

Let’s talk differences and similarities between novel and TV adaptation. Much of the dialogue is repeated word-for-word. Kings Cross station becomes Stansted Airport as there is more space there for the directors to play. The final chase, which on TV includes moments of high drama and low comedy, is expanded from the novel. But the plot is otherwise fairly faithfully reproduced. The TV cast are excellent. Whereas I’ve been keen to point out that – much as I love them both – the Shetland novels are better than the TV series, Slow Horses the novel and Slow Horses series 1 are equally fine, but different experiences, each leaning into the advantages of its medium. In particular, Herron is an excellent writer with a distinctive voice. 

It takes a while to get used to Herron’s prose. Sometimes you have to read the sentences a few times because you are in awe that they are so good. He is at pains to point out that the world of the horses is the product of deliberate decisions. So the chairs in Slough House are uncomfortable, not because no one could be bothered to furnish a comfy office, but because those who labour here are not so well regarded that their comfort is deemed as being of account. That’s a beautifully-crafted sentence. The labourers have no agency and the decision-makers are faceless.

The whole of this world is constructed with clues looking for meaning; these clues are the result of strategic thinking, random small thoughts, or downright sloppiness: the very nickname of slow horses arises from snobbishness about Slough. This is a world where status is all: the agents at the Park are superior to the horses; it isn’t always clear whether the horses are superior to the dogs. There’s a juvenile aspect to the one-upmanship and the lazy nicknames: ‘Lady Di’ and ‘Spider’ represent the Park; the horses are often well—meaning but by reputation incompetent (but we aren’t told about the Park’s mistakes in the same way). Only Jackson Lamb, head horse as it were, is in some way above it, and he’s a deliberately ambivalent character evoking both admiration and disgust in equal measure. Spy tradecraft is respected. There’s no sense of fair play other than that Lamb will from time to time stand up for the joes under his command.

Herron tells the story with multiple points of view: in particular, we get to know River Cartwright, who is good enough at this game to be credible, but new enough to observe, and for us to learn through his eyes. But at other points, Herron veers between cynical, sarcastic and expository quite happily. We’re on the inside and at times we feel like we’re part of this gang. Should we want to be? I’m not sure. We root for the horses but never for the dogs: we’re complicit in the hierarchy and in a bleak world. Should spooks be idealistic? I’m not sure about that either. But in the hands of a writer less able to – well – entertain, Slough House would be as bleak to read about as its chairs are to sit on. As it is, book 2 is shining on the shelf, and has muscled its way to the front of the TBR queue. Go read, go watch.