River is trapped in France. Back at Slough House, the Dogs have come for Lamb.

A naive agent makes a discovery about the Westacres bomber. Lamb suspects that David knows more than he’s letting on.

A London bombing puts Taverner under pressure. When River grows concerned for his grandfather, Louisa encourages him to go for a visit.

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

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

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

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

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

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

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