Michael Gough was on the shortlist for Captain Potter. The role eventually went to John Stratton.
Well if you're wrong it won't matter.
Dr. Matthew Roney: No. I'll just retire. They'll stick me alongside the Piltdown forgeries as a horrid warning.
Calendars seen on sets throughout the serial always show the episode's actual live transmission date. Whilst providing a uniquely contemporary feel for BBC viewers of the original 1958/9 screenings, it make no sense within the internal narrative.
All commercial releases prior to the 2004 DVD box set are an edited omnibus version. Several scenes written to allow actors to move between sets during the live broadcast were removed, along with the opening and closing titles.