(Series 13, Episodes 5-8)
Summary: At the edge of the universe, Doctor Who plays fast and loose with theoretical physics, as the Doctor and Sarah are menaced by a pencil scribble. An investigative team in low-cut spacesuits with a penchant for orderly interrogations, arrive to rescue obsessive scientist Sorensen, only to find that anti-matter causes excess hair growth. Commander Salamar must be terribly fit, what with all the conclusions he keeps jumping to, and the model work is excellent.
Watch it because: Reassuringly reasonable Vishinksy.
Original Air Date: 27 September – 18 October 1975.
Doctor: Tom Baker.
Companions: Sarah Jane Smith (Elisabeth Sladen).
Writer: Louis Marks.
Director: David Maloney.
Producer: Philip Hinchcliffe.