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 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.

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

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

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

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

Lamb questions David about France as River comes face to face with the enemy.

Impossible decisions are faced and sacrifices are made.