The team is reeling from the shocking discovery of a mole among them, and as the Soviet plot continues unabated, it is up to Wendy to give the team the break they need. Meanwhile, when Sarah finds herself in danger, Alan is forced to make a decision that can make or break their relationship. Joe has trouble of his own when leaked information threatens the investigation and the lives of the team.
As the Montags settle marital differences the group is aware of the traitor in their number. Bobby is informed that Philip Denmoor, a disfigured former bomb disposal officer is in touch with Colin Blakefield, who told Sarah about Operation Glass and has since disappeared. Both have been in contact with the IRA, who Daddy believes may be linked to the Soviets. Posing as a nurse Wendy visits Denmoor and a detonator is discovered, with which he escapes. Helped by Kate Wilkinson Joe and Jim expose the traitor but are unable to prevent a bomb blast in the capital.—don @ minifie-1