The blurb:
At Slough House—MI5's London depository for demoted spies—Brexit has taken a toll. The "slow horses" have been pushed further into the cold, Slough House has been erased from official records, and its members are dying in unusual circumstances, at an unusual clip. No wonder Jackson Lamb's crew is feeling paranoid. But are they actually targets?
With a new populist movement taking hold of London's streets and the old order ensuring that everything's for sale to the highest bidder, the world's a dangerous place for those deemed surplus. Jackson Lamb and the slow horses are in a fight for their lives as they navigate dizzying layers of lies, power, and death.
I don't usually do this full spoilers ahead.
This is probably one of the strongest slow horses books, I think; very tangled webs.
I mentioned in my review of Joe Country that it benefited from having read all the other books to get the full belt of what was going on. Well, Slough House leaves Joe Country for dead in that regard; it really goes back to the first novel for its victims. At the end of Joe Country, we found out that Slough House has been wiped from service records. The slow horses are still getting paid, but that's about it, everything else about them has been covered up. Slough House explains why: Diana Taverner is using the slow horses as practice targets for new agents. Fortunately the slow horses work this out relatively quickly, because they have one thing the new agents don't, and that's experience. They might be losers but they're not complete idiots.
Unfortunately, Taverner's little game has unexpected side effects that tangle up with side effects from another little game she's running. The Gay Hussar (if Mick Herron is ever unexpectedly found dead, it'll be because Putin had him murdered for characters constantly referring to him like this) attempted the murder of a defector in the UK, with civilian casualties, by using novichok—basically Herron incorporating real-life events into the Slough House chronology. Taverner wanted to respond in kind but was unable, due to lack of resources. Capitalism to the rescue; a f(r)iendly group of patriotic billionaires secretly funnel funds to her via disgraced former MP Peter Judd and suddenly she has the resources to return fire, having the agents who carried out the novichok killings murdered back in Russia.
It's a deal with the devil, of course, because of course they'll want something in return. YouTube whizkid Damian Cantor in particular wants her to appear on one of his shows, and manages to insert one of his security dudebros in Regents Park. He likes to feel connected to the action...and also has a big mouth, wanting to share what he knows. Shades of that old adage about 'those who know, don't talk; those who talk, don't know.'
One of the things that somehow makes it back to Russia is that MI5 has a secret, off-the-books assassination squad hanging around in London. So what do you think happens—of course, someone takes the fact that Slough House has recently been wiped off the map as evidence that they are said hit squad. Thus suddenly we have ex-slow horses dropping like flies. And this where the background reading comes in, because two of the deaths are of former slow horses, Struan Loy and Kay White, not seen since Lamb kicked them to the curb for betraying him way back in Slow Horses.
It also allows us to appreciate just how knocked sideways River Cartwright is by the return of Sid Baker, who was shot in the head in Slow Horses. Sid's death is something that's haunted him throughout and, when he's already a mess because of his grandfather's death and the fact that his father is half cult leader and half batshit, her return is further destabilisation for him. It also triggers him to act both bravely and not as wisely as he might—this is a continuing flaw of his, he goes straight into hero mode and doesn't spend nearly enough time in cynical bastard mode for someone who spends time around Diana Taverner and Jackson Lamb.
So, Diana Taverner compromised, check; slow horses under threat, check; murderous Russians roaming the landscape, check. It's a complex setup but never relies on coincidence or someone having a sudden insight caused by random words from anyone else. Sid is believably damaged after being shot in the head—there's nothing James Bond-ish about it. River gets to be a hero before...well, before not-good things happen at the end of the book.
The only sour note I found was Diana Taverner's deal with the devil. The woman lives and breathes power and politics; there's no way she would be surprised that capitalist billionaires might want a quick quid pro quo in return for handing her scads of money, no way she wouldn't know that people like that aren't used to hearing no. She believes in London rules (Moscow rules, cover your back; London rules, cover your arse) like the Pope believes in God, and it beggars belief that she's been entangled so completely, so easily.
Aside from that one bum note, I really enjoyed this one, and I'm looking forward to Bad Actors.
Started: 18 November 2025
Finished: 23 November 2025
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