When Section D receives intelligence that a plane has crashed near an American airbase on UK soil, they fear that it may have been shot down on purpose. Meanwhile, Ros is kidnapped by Yalta, an international group of double agents planning to thwart US dominance in world politics, but she soon learns that it’s all just a ploy to get her to join them.
Back at the Grid, a source from the MoD tells Ros and Jo that the Americans were illegally testing their new spy jet, Aurora, in UK airspace when it crashed. When the team discovers that the plane tracked MI5’s recent operation in Tehran, it becomes clear that the US was behind the false intelligence which led to MI5 setting off the bomb there which, in turn, would justify military action.
Livid that the US is prepared to manipulate Britain, Ros makes contact with Yalta. Once again it seems that Ros is on the path to becoming a traitor.