“If Moscow rules meant watch your back, London rules meant cover your ass.”

MI-6, home of James Bond and George Smiley, is legendary. MI-5, its less famous cousin, deals with domestic intelligence in the UK. It has generally not been featured in novels, perhaps because stalking terrorism on the streets of Brixton seems inherently less glamorous than running agents across the Wall in Berlin?

Whatever the reason, Mick Herron steps in to redress the imbalance in his Slow Horses series of novels. It is far from a glamorous portrayal, though: Herron’s books are set among the MI-5 rejects dumped in a distant London borough far from the MI-5 hub in Regents Park. The ‘slow horses’ of Slough House are led by Jackson Lamb, ex-handler of agents in Europe, now a grimy, washed-up has-been. His team, such as they are, include Catherine Standish (ex-alcoholic), Min Harper (who left a top-secret file on the Tube one day), Louisa Guy (who was tailing a gunrunner, and lost him), Roddy Ho (tech genius who has spent many hours hacking Regents Park files to find out why he has been relegated to Slough House). River Cartwright is young and keen, and resentful about being stuck in Slough House. And most recently, there is Sid Baker, who is so bright and smart that no one can figure out why she is here rather than at Regents Park.

Slow Horses, the first novel in the series, opens with a thrilling action scene. River Cartwright is at Kings Cross station, fed information via an earpiece, watching for a terrorist with a suicide bomb:

young male, brown skin, white tee, blue shirt

Or is it blue tee under a white shirt?

The target pulled a cord on his belt.

And that was that.

This, it turns out, is a training exercise, but the resulting disastrous shutdown of Kings Cross station is why River ends up at Slough House. The rumour is that he would have been fired if it were not for the fact that his grandfather is a retired MI-5 legend. He is never, never allowed to forget the reason for his exile.

The Slough House employees spend their time with tedious busywork such as examining the 1990s driving license applications, or cross-correlating old flights to Syria with other bureaucratic bits of information. Jackson Lamb presides over the dead-end assignments with sarcastic wit designed to keep the workers firmly in their place.

If [I wanted to put someone under surveillance], you think I’d pick you? Supposing I wanted it done without dozens of innocent bystanders getting killed. Think you could manage that?

We’ll watch it on the telly with everyone else. But we won’t do anything. That’s for the big boys and you lot don’t play with the big boys.

You’ve got papers to shuffle.

Yet, the slow horses are burning to get back to Regents Park, somehow, and do real work. Especially River, who has an anti-authoritarian and independent streak.

Several parallel events converge. The slow horses’ task of surveilling Hobden, a right-wing journalist, puzzles everyone: why would this job be given to them? A young Asian man is kidnapped and an unknown right-wing group threatens to behead him in 3 days; is this related to the Hobden situation? Diana Taverner, the ambitious second-in-command at MI-5, has her own calculating agenda and spies everywhere, including at Slough House and in the right-wing group. In a nicely modern twist, the head of MI-5 is also a woman, Ingrid Tearney.

The plot is clever, too. Nothing is quite what it seems, and the emergence of the ‘truth’, such as it is, layer by layer, is skillfully done. There is double-crossing. There are twists. There are plenty of ambitious personnel each covering their ass (‘British rules’) and watching their backs (‘Moscow rules’).

Herron is good with snappy dialogue and plot, and not too bad with description. He doesn’t have the elegance or depth of Le Carre or Alan Furst, but his writing is good enough for this dry, wry, more entertaining novel.

There wasn’t much of a moon, but that hardly mattered. River was opposite Robert Hobden’s flat again. Less than forty-eight hours ago rain had been falling in torrents, and River had been on the pavement, stealing shelter from an overhanging window. Tonight it wasn’t raining, and he was in the car — if a warden came, he’d move. From behind Hobden’s curtain, a thin light shone. Every so often, a shadow fell across it. Hobden was a prowler, unable to sit still for long. Much as River hated to admit anything in common with him, they shared that much.

The novel is full of Britishisms:

He’ll turn out to be a Muslim squaddie.

Half of a bitter and a jazz mag.

You don’t think Hobden’s got the nous to put this together?

He’s just taking the piss.

Slow Horses was recently made into a TV series starring Gary Oldman as Jackson Lamb, perhaps overplaying his role a bit, but still very much in the character of Lamb. Kristin Scott Thomas is brilliant as Diana Taverner. The other members of the team are not famous names, but all of them are very good indeed.

The TV series follows the book quite precisely for its first half, but then diverges. The book has a quieter, perhaps more realistic turn of events, while the TV series amps up the action and gives all of the slow horses more initiative and adventurous activity. I slightly preferred the more ambiguous, and darker, ending of the novel, but the actors in the TV series are good enough that the events are still riveting.

Quite delightfully distinct from any other spy or thriller that I’ve read, both the book and TV series are worth a look.