No doubt this will be seen as a controversial choice to come in this low in this listing, as this departure is often lauded as the greatest Doctor/Companion scene of all time, usually by people who I’m assuming have only seen the last 10 minutes of The Hand of Fear part 4 and no other episode of Doctor Who. In my view this departure always felt too contrived to be wholly satisfactory. There are good points to it - Sarah discovering that the Doctor has dropped her off in the wrong place on Earth does bring a smile and the whole scene is nicely acted and beautifully played, and is moving in some respects when the Doctor does say goodbye to Sarah and we see Sarah’s reaction that he’s being serious. On the flip side is the abruptness of the departure for such an important, long running regular character - there certainly isn’t a build-up in the story to Sarah leaving. In contrast to many other companions (who are still to be featured in this list) Sarah doesn’t really have a departure story per se - she has a departure vignette. The Hand of Fear as a whole doesn’t set up her departure at all. Instead the adventure ends a few minutes early, and the departure scene occurs, pretty much unconnected to the adventure. Matters are not helped by the sudden tantrum that Sarah suddenly throws which causes her to pack her bags (conveniently for her departure from the TARDIS a couple of minutes later) and comes across as very contrived - both in terms of what sets it off (basically,the 4th Doctor acting typically like the 4th Doctor and absent-mindedly not listening to her for a few minutes) and how out-of-character it is for Sarah.

The feeling of contrivance doesn’t end there - while it may be understandable for the Doctor to believe that he can’t take her with him to Gallifrey,  he departs Gallifrey again at the end of the next story and it is quickly apparent he could go back for her and doesn’t bother to do so. If the Doctor is as fond of Sarah as this scene - and their friendship over the past three years - suggests, it doesn’t feel convincing or persuasive that he doesn’t go back to visit her. To put it this way, if you were to provide a quick one-line summary of the reasons why each of the companions depart the TARDIS, it would feature examples ‘“Susan falls in love with a human and stays with him in his own time on Earth”; “Ben and Polly decide to stay in their own time after the TARDIS returns there”; “Jamie and Zoe are returned to their own time by the Time Lords when they put the Doctor on trial and exile him to Earth”; “Jo falls in love with a scientist that reminds her of a younger version of the Doctor”. When you get to Sarah, the summary would be “Sarah leaves the TARDIS as the Doctor is called to Gallifrey and believes that he can’t take her with him, and then he doesn’t bother to come back for her once he’s done there”. It just feels like the makers of the show at this time couldn’t really think of a good reason for her to leave the show permanently and so they come up with a contrived reason that has nothing to do with the character, nor the character’s relationship with the Doctor, and a reason which isn’t built up at all in the story or in the stories leading up to her final story. For such a major and popular character, that seems a bit of a shame and a missed opportunity.