The group go underground as part of the establishment: Blunt is close to the royal family, Maclean joins the Foreign Office, Burgess is in MI5 and Philby is a right-wing journalist. Spain tests Burgess and Philby. Burgess's lover Julian Bell goes to die fighting for the republic. However, Burgess can't blow his cover to support him and is affected by this betrayal. Philby, reporting from Spain, fails to carry out orders from his Soviet control, Otto, to assassinate Franco. Philby flees Spain and survives, but his betrayal costs Otto his life.When Stalin signs a non-agression pact with Nazi Germany, all four feel betrayed as their struggles against fascism have been turned upside down. (thetvdb.com)