sentences:  The plots of the unmade serials also vary.A theme of a civilisation where women are dominant was proposed twice—once for "The Hidden Planet", and again for "The Prison in Space".In some cases, elements of unmade serials were adapted, or were moved from one serial to another; for example, "Song of the Space Whale" was intended to be the introduction of Vislor Turlough until it was repeatedly set back, causing "Mawdryn Undead" to be Turlough's first appearance.