Slough House is the dumping ground of the British Secret Services. Left a briefcase filled with state secrets on the bus, accidentally punched the Prime Minister's wife or nearly blown up a major metropolitan train station during a training exercise? Then Slough House is where you end up; doing stultifying and demeaning administrative tasks under the baleful eye of station commander Jackson Lamb (think a bitter and burned out James Bond).
The Slow Horses are only around until they can be made to quit, or get back into the good graces of their higher ups at MI6.
The first in a series of novels that reads as a cross between The Office and Tinker Tailor Soldier Spy.