It's 1965, and Doctor Who has been off the air for another 6 week break before starting its 3rd Season on the 11th September. Once more a healthy 8 million plus viewers are regularly watching the show, peaking to an incredible 11 million by the third week of the Doctor and his companions encountering the Drahvins, Rills and Chumblies in "Galaxy 4". After a strangely sedate drop back to 8 million for the cast's 4-week sojourn in ancient Troy (another "historical dip"?), the viewers return for the almost obligatory annual Dalek romp. This time a full 12 weeks of the rampaging Pepperpots sees the viewers peak at 10 million and rarely drop below 9. The Daleks can still pull the crowds...although there is an unusual drop back to 8 million for the episode "The Feast of Steven", but as this was broadcast on Christmas Day itself this might simply be down to viewers being too busy with Christmas to watch television.
However, after 3 months of solid Daleks, Doctor Who heads into 1966 with a drop in viewers from which it never really recovers. The four episodes set in 16th Century Revolutionary France see the figures slip below 6 million for the first time since Season 1, and although things pick up when the Doctor and companions arrive on the Ark in the far future, the show is now only peaking at 8 million viewers. By the time the Doctor travels to 19th Century Tombstone for "The Gunfighters" the viewing figures are sliding inexorably towards the 5 million mark, somewhere they have never been since the very first episode of the show. Whether this is down to viewer dissatisfaction with William Hartnell's performance, the changing cast (and loss of the popular Ian and Barbara), what's on the "other side", or simply changing audience expectations, we may never know. But as Season 3 closes, not only is the era of individual story titles now over, but "The War Machines", parts 1-4 (arguably the template for Doctor Who's most popular storyline - the Contemporary Sci-Fi Menace) attracts less than 6 million viewers.