London's Slough House is where the washed-up MI5 spies go to
while away what's left of their failed careers. The "slow
horses," as they’re called, have all disgraced themselves in
some way to get relegated here. Maybe they messed up an op badly
and can't be trusted anymore. Maybe they got in the way of an
ambitious colleague and had the rug yanked out from under them.
Maybe they just got too dependent on the bottle—not unusual in
this line of work. One thing they all have in common, though, is
they all want to be back in the action. And most of them would
do anything to get there─even if it means having to collaborate
with one another.
Now the slow horses have a chance at redemption. An old Cold
War-era spy is found dead on a bus outside Oxford, far from his
usual haunts. The despicable, irascible Jackson Lamb is
convinced Dickie Bow was murdered. As the agents dig into their
fallen comrade's circumstances, they uncover a shadowy tangle of
ancient Cold War secrets that seem to lead back to a man named
Alexander Popov, who is either a Soviet bogeyman or the most
dangerous man in the world. How many more people will have to
die to keep those secrets buried?