In this episode, a nuclear bomb is set to explode, triggered by a Russian sleeper agent who was part of Operation Tiresias. As Parliament and the Royal Family are evacuated, the nuclear threat to London is eliminated when Ros and Lucas are able to turn Connie James and elude an FSB kill squad. Connie was killed defusing the bomb by its conventional explosives. Seconds before the bomb exploded, Connie revealed that it had not been Harry who sold Lucas North out to the Russians as Lucas had always believed but rather herself. The episode concluded with Harry, conscious but with his mouth taped shut, in the boot of a car being zipped up in a body bag by Viktor Sarkisian, head of the FSB's London station.