Simon has just arrived in Geneva, but – as always – his leisure time turns out to be very brief.  Karel Jorovitch (Joseph Fürst) is a brilliant Russian scientist keen to defect and be reunited with his daughter. Jorovitch and Simon briefly meet and after Jorovitch later disappears, Simon is approached by Irma Jorovitch (Penelope Horner). She tells him that her father has been abducted by the Russians and is likely to be executed very soon …

Joseph Fürst, an impressive actor who seems fated to always be remembered for his hammy turn in Doctor Who (nothing in the world can make me forget it) impresses as the twitchy Jorovitch. After featuring so heavily in the first act, it’s slightly surprising that he then disappears from the story, but the reason for this is made clear at the end.

A stand out turn comes from Yootha Joyce as Milanov, the senior KGB operative charged with ensuring Jorovitch doesn’t step out of line. Joyce will always be best remembered for her 1970’s comedy work, but her cv during the 1960’s showed that she was equally adept at drama. Possibly owing a debt to Rosa Klebb, Milanov might be something of a cliché figure (the implacable KGB operative who’s a stranger to pity and compassion) but Joyce was too good a performer to let Milanov simply exist as a cardboard villain.

Sadly for her, Milanov has to rely on some inept muscle – namely Krill (Godfrey Quigley) and Pytor (Anthony Booth). Simon is able to run rings around them time and time again – most entertainingly during a fight in his hotel room (where prop furniture shatters with reckless abandon).

Guy Deghy as the always apoplectic Inspector Oscar Kleinhaus, Robert Crewdson as Mikhail Zhukov (who sports a strange beard) and Sandor Elès as the phlegmatic hotel receptionist Andre fill out the minor roles.

The major guest role goes to Penelope Horner as Irma. The second of her three Saint appearances, Horner gives a winningly winsome performance as Irma – although there always seems to be something unfathomable about her.

All is revealed at the conclusion of the episode when  – spoiler alert – she turns out be yet another Russian agent and not Jorovitch’s daughter after all (Jorovitch has actually sought and received asylum – so the Russians decide to spin Simon a tall tale and hope that he’ll do their dirty work for them).

This brings the story to a neat conclusion, although it doesn’t quite satisfy me (why did Irma turn up in Geneva long before Jorovitch defected?). But minor quibbles apart, this is entertaining fare with Roger Moore in fine quipping form and the stock footage integrating very well with the studio material. Four halos out of five.