The Slow Horses of Slough House
Many espionage stories' protagonists fall into one of two categories...
The first category is the espionage professional: Ian Fleming's James Bond, Daniel Silva's Gabriel Allon, and John LeCarre's George Smiley all come to mind. Cool, calm, collected, they are trained and paid to do their nation's dirty work.
At the other end of the spectrum is the unwitting amateur that finds themselves thrust into a situation which they are seemingly ill-equipped to deal with. Eric Ambler's and Alan Furst’s novels often featured such main characters.
Bridging--or perhaps stumbling into--the gap between espionage professionals and bumbling amateurs are the "Slow Horses" of Mick Herron's Slough House series. They are failed MI5 agents who have been sent to Slough House, where they while away the hours and days performing the most menial of administrative tasks. The agency hopes they will lose all hope and quit of their own accord, saving it the time and expense of firing them.
Presiding over the Slow Horses is Jackson Lamb, a late-middle-age Cold War veteran now serving his own penance. Lamb is utterly disgusting in speech, manner, and personal hygiene. He chain-smokes, drinks booze all the livelong day, and showers... very rarely. Exactly why Lamb is exiled here is not clear, but it's not difficult to imagine his higher-ups wishing to distance themselves from him.
Lamb's prime objective seems to be to frequently remind his employees why they are at Slough House and to snuff out any faint hope they may have had of ever returning to real MI5 work. Despite that, we find that he is actually very protective of his Slow Horses ("they're f---ing losers... but they're my f---ing losers").
It would be easy to underestimate Jackson Lamb, and many have, to their detriment. As his "losers" stumble into situations that are probably beyond their capabilities, they will need Jackson Lamb's wisdom and expertise--and his willingness to protect his people at all costs.
Herron has thus far written 8 novels in the series and a few shorter works. If you like well-written espionage stories served with a large dose of humor, I recommend that you check it out. But I do suggest you read the books in order, starting with Slow Horses.
By the way… I would be remiss if I failed to mention that these books are the basis for the excellent Apple TV series Slow Horses, starring Gary Oldman as Jackson Lamb.