Lamb and Katinsky go head-to-head. Ho finds himself trapped on a train with a Russian assassin. Season finale.
Lamb orders his Slow Horses to walk into traps. River believes something alarming is heading toward London.
Louisa makes her move on Pashkin. Catherine makes moves of a different kind when she plays high-stakes chess with a sinister stranger.
River gets cozy in the Cotswolds while searching for a sleeper agent. Min discovers Russian drinking games are the most brutal of all.
Lamb liaises with a Russian defector who may hold a clue to sleeper agents. River is on the trail of a ruthless assassin.
Arya makes progress in her training. Sansa confronts an old friend. Cersei struggles. Jon travels.