River Cartwright is ousted from MI5 and finds himself in a place worse than purgatory: Slough House, dumping ground for failed spies.

River and Sid join forces. A misfired gun has dire consequences.

Slough House is the unlikely venue for a secret romance, but events take a dark turn when a dangerous encounter becomes deadly.

Taverner sends the Dogs to hunt down Lamb and the Slow Horses. River holds the secret to saving the gang.

The Slow Horses must disappear to avoid capture by MI5. Lamb and River head to The Park to outwit Taverner.

Taverner and the Slow Horses attempt different approaches to locate the kidnappers and Hassan. Ho makes a shocking discovery about Sid.

Jackson Lamb is on high alert after a former spy is found dead. Min and Louisa are tempted by an offer from outside Slough House.

Lamb liaises with a Russian defector who may hold a clue to sleeper agents. River is on the trail of a ruthless assassin.

River gets cozy in the Cotswolds while searching for a sleeper agent. Min discovers Russian drinking games are the most brutal of all.

Louisa makes her move on Pashkin. Catherine makes moves of a different kind when she plays high-stakes chess with a sinister stranger.