London Rules (Slough House book 5) by Mick Herron (book review).
In the build-up in ‘London Rules’ by Mick Herron, you could also miss the significance of Roddy Ho being nearly run over by a car and saved by fellow slow horse Shirley Dander and still not realise it, being more upset that his mobile phone was broken. Jackson Lamb is rather dismissive of the situation, but Dander, along with River Cartwright and Louisa Guy, reluctantly decides that something is wrong and chooses to keep an eye on Ho. Oh, Lamb’s definition of London Rules is ‘Mind your arse’.
The situation is that while they are watching Ho, Lamb monitors Ho’s home and prevents a second attempt on the computer whizz’s life. This action, in turn, attracts the attention of Regent’s Park, which intervenes at Slough House, takes Ho for interrogation, and places the others under lockdown, overseen by the chief dog, Emma Flyte.
There is, however, a connection to a series of other acts, including murder, and the bullet shot at Ho belongs to that deadly incident. JK Coe reveals that MI5 is implementing this plan. Lamb holds Flyte at gunpoint, while the four slow horses divide into two pairs to go after two politicians who are likely to fit the profile of being assassinated. This detail reveals a significant plot point.
In fact, much of this story contains spoilers, and for a significant portion of the time, the slow horses are on the periphery of the events, leaving you unqualified to see what they are doing. Herron frequently initiates significant action and then provides a detailed description later on, which may seem unusual in a spy drama. The story featured a significant number of talking-head scenes rather than action-packed ones. You can do a lot if you bury it in descriptive detail.
A lot of loose ends are completed by the end of the story, and although there are two more novels after this one, I got the impression Herron was either at the end of his contract or he was considering the book as his last ‘Slough House’ novel at the time.
Looking up the release of season 5, author Mick Herron reveals he has done a second version of this story for TV. I can see why. Slough House doesn’t really get involved until a quarter of the way into the book, and then it unveils how Roddy Ho was involved much further in. A lot of it is also talking heads, which isn’t always advisable in a TV series. Actor Christopher Chung, who plays Roddy Ho, in a BBC interview says he had a lot more to do in the interrogation scenes and was more prominent than in the earlier TV stories. In the novel version, we actually see him do less.
OK, now for a look at the TV version. Like previously, I pulled a copy from China and was surprised how quickly it was available over there after it finished in the UK. Never look a gift horse in the mouth, especially as the auction site dealer was also offering a lot of new series at a discount. Some of these new series are also in the science fiction genre, so they are likely to appear here as well. You don’t even have to turn off the Chinese subtitles this time.
The opening episodes match the book, with only minor details different. Lamb’s socks don’t always have holes in them all the time. Roddy Ho’s bed mattress is full of water, so Lamb prefers to sleep on a chair rather than be seasick.
It isn’t until the fifth episode that there is a significant change, which is such a spoiler. I can’t say much about it, but I understand why Herron suggested it, as MI5 is portrayed in a particularly negative light, especially regarding the first desk.
Clearly, there is much more work to be done for the slow horses, and this situation raises questions about the competency of Regent’s Park, especially considering how often they have the upper hand. Mind you, I doubt if Jackson Lamb would want any of them at Slough House. Their success is due as much to luck as it is to their own deliberation. On the other hand, is complete competence in the espionage field necessary, or should we focus on achieving results?
GF Willmetts
November 2025
(pub: Baskerville, 2018. 344 page small enlarged paperback. Price: varies but get the wrap pack if you want them all. ISBN: 978-1-399-80308-3).
