Covert CIA agent Martian is called back to London Station.
A spooked source threatens to put an operation at risk.
Martian finds a needle in a haystack and confronts Sami about London.
Henry and Martian run diplomatic interference. Danny walks a tightrope.
Henry sends Owen to Minsk in a hunt for clues. Martian sets a rat trap.
Martian scrambles to unravel Cossack's game. Osman plays his hand.
Bosko is briefed on Valhalla. Martian, Henry and Naomi strategize a play.
Martian's approach doesn't go to plan. Sami makes a startling confession.
Martian buys time with a bluff to Langley. Danny crosses the Rubicon.
Bosko shares a grim truth. Martian makes a devil's bargain.
