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