It is an episode where Special Branch has plenty of suspicions but nothing concrete.
Then there is a German who hangs about the yacht club. Karin is married and her husband's activities have come to the attention of the Swedish police. An unhappy marriage, he drinks too much at the yacht club, he might be having an affair with a younger Swedish woman Karin who he plans to take on a sailing trip on his boat. Jordan and Inman keep tabs on Clifford who has a chaotic private life. Clifford is looking forward to giving a talk in Budapest but that is suddenly cancelled under Moxon's orders who believes that the Russians are interested in pursuing Clifford or might have already got him. Dr Clifford (William Lucas) is a top scientist working in a research laboratory which has previously had a security leak from a secretary. The episode is a reworking of themes explored by Special Branch in previous episodes.
