The Daleks hatch their deadliest plan. Although Steven and Vicki leave the TARDIS, the Doctor is briefly joined by Dodo and Katarina followed by Ben and Polly.
William Hartnell continues his journey as The First Doctor, accompanied by companions Vicki (Maureen O’Brien) and Steven (Peter Purves). In the third story The Myth Makers, Vicki departed and was replaced by Katarina (Adrienne Hill). Katarina’s tenure was brief, the character being killed in episode 4 of the following story, The Daleks’ Master Plan. In some companion lists, Sara Kingdom (Jean Marsh) is included as a companion, though her appearances were limited to later episodes of the serial The Daleks’ Master Plan.
Dodo Chaplet (Jackie Lane) joined the Doctor and Steven in the next serial, The Massacre of St Bartholomew’s Eve. There were no changes in the primary cast until Steven’s departure in the penultimate story, The Savages. In the final story The War Machines, Dodo also departs, and the Doctor was joined by Polly (Anneke Wills) and Ben (Michael Craze). Like the previous season, the cast of companions had changed from start to finish.