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.

Lamb orders his Slow Horses to walk into traps. River believes something alarming is heading toward London.

Lamb and Katinsky go head-to-head. Ho finds himself trapped on a train with a Russian assassin.

A romantic relationship in Istanbul ends badly. Lamb hits the panic button when one of his Slow Horses fails to show up for work.

River has to steal something out of the Park to save a life. Lamb realizes a stranger game is afoot.

Marcus and Shirley face Lamb's wrath. River discovers revenge is a dish best served cold.

Tearney makes a bold move. The Slow Horses assist the Tiger Team, unaware of their hidden agenda. Lamb and Ho take a road trip.

Taverner and Tearney face off for control of MI5. River and Louisa find themselves caught in the crossfire.

The Slow Horses fight for their lives. Lamb shares some devastating truths with Catherine.