The 13th and final episode of the British-German science fiction series Star Maidens premieres on ITV in the UK. (Not all regional ITV affiliates carry the show at a specific time; this episode guide reflects the dates for the broadcast premieres of each episode on Scottish TV.) 
With Adam and Shem captured, Earth and Medusa prepare to exchange prisoners. As arrangements are made, another signal is found in deep space, originating from somewhere other than Medusa; the Medusans suddenly accelerate the timetable for the prisoner exchange. When the signal is played back on Earth, it makes Shem violently ill, and Professor Evans is only able to get Fulvia to tell him that this is a matter between Medusa and its ancient enemy from another galaxy.
written by Otto Strang
directed by Freddie Francis
music by Berry Lipmann
Cast: Judy Geeson (Fulvia), Lisa Harrow (Liz), Gareth Thomas (Shem), Pierre Brice (Adam), Christian Quadflieg (Rudi), Christiane Kruger (Octavia), Derek Farr (Evans), Dawn Addams (Clara), Uschi Mellin (Andrea)
Notes: This is the final episode of Star Maidens; the unnamed (and mostly unseen) enemy hails from Proxima Centauri, just like the planet Medusa, and they are said to have fed upon the Medusans during past clashes.
LogBook entry by Earl Green