Corrected entry: At the climax, the Doctor and Morbius engage in a mental duel. When the Doctor appears to be losing, the faces of the First Doctor appears, followed by several other adult male faces in various period clothing. The suggestion appears to be that these are previous incarnations of the Doctor prior to William Hartnell's version. Indeed, this was the idea at the time the story was broadcast (the faces themselves were those of various production members). However, if the William Hartnell incarnation was not the first Doctor Who, but the fourth (at least) that goes against the entire continuity of every Doctor Who story..