s3 and s4 of dr who are really interesting bcos as you watch them you can see the show like. Floundering.
1: Ian and Barbara leave. they write in Steven as a replacement
2: they juuust manage to establish a new Vicki & Steven dynamic in Time Meddler and Galaxy 4 but it's still a work in progress. Galaxy 4 is actually a retooled Ian and Barbara script that they put Steven in.
3: Verity Lambert quits as producer, replaced by John Wiles
4: Maureen O'Brien (Vicki) either abruptly resigns bcos her agent ended her contract or is fired. evidence unclear.
5: Production is left scrambling for a replacement, introduce Katarina
6: They realise that Katarina's backstory as an agent Trojan is going to make things difficult from a writing standpoint and decide to write her out. The turnaround on this is so rapid that the first scene Adrienne Hill shoots is the pre-filming for her death.
7: They write in Sara Kingdom. Either she was intended to be a temporary character or Jean Marsh declined their offer of a permanent contract. Either way she lasts 8 episodes.
8: In the Massacre they introduce a new character, Anne Chaplet, who is from 16th century France, and then realise they are going to have the same problem they had with Katarina and opt not to make her a companion.
9: The final scene of The Massacre introduces Dodo. The whole sequence has the air of a rush job tagged onto the script, possibly after they decided not to keep Anne around?? It's just unbelievably lazy but seems to be an attempt to go back to the Basics of the show w a contemporary 1960s companion scooped up against her will.
10: John Wiles leaves as producer and is replaced by Innes Lloyd.
11: At this point I think they might have decided to retool Dodo from a teen character like Susan into a young adult, perhaps in an attempt to make the show a bit Hipper?
12: Throughout all of this William Hartnell has been becoming progressively sicker with a chronic vascular disease. Around the time Innes Lloyd takes over the decision is reached they he has to be replaced if they want to continue the show.
13: As part of gearing up to to replace William Hartnell, they unceremoniously end Peter Purves' (Steven) contract. The stated reason is that they don't want to keep companions around for more than 1 year anymore but reportedly this might have been done bcos he and William Hartnell were friends and they thought firing him might help with pressuring William Hartnell to quit.
14: Jackie Lane's (Dodo) contract comes to an end 2 episodes into a 4 parter (The War Machines) and she is also unceremoniously terminated. Dodo is written out as abruptly as she was written in. No-one seems to know exactly why Jackie Lane was fired.
15: The War Machines introduces new companions Ben and Polly, who are basically like Ian and Barbara except younger and sexier. The ending of the story has them accidentally wander into the TARDIS as it's about to take off, thus restoring the previous status quo of the Doctor + contemporary companions who want to be taken home.
16: At one point in the development of The War Machines the companions going forward were gonna be Ben and Dodo which suggests Jackie Lane and Peter Purves' firings were 2 separate decisions. Season 3 comes to an end.
17: Season 4 opens with a historical serial (The Smugglers) followed by The Tenth Planet ie the first regeneration. Patrick Troughton takes over.
18: The immediately next serial (The Highlanders) introduces Jamie (Frazer Hines). Frazer Hines is originally contracted for 4 episodes but the producers decide to make him a permanent cast member. The ending of Highlanders is re-shot to accommodate this. Apparently they were able to do this easily bcos Frazer's contract had always included an option for a further 8 episodes. A wildly reported myth is that this happened due to positive audience reception but this seems to be flatly untrue as the reshoots occurred before episode 1 of Highlanders aired.
19: The scripts for the new few serials are hastily re-written to insert Jamie.
20: They is, apparently, some tension on set at this point. Anneke Wills and Michael Craze (Polly and Ben) seemingly do not want Frazer there and make this clear to him. I don't know if anyone has ever explicitly said so but presumably they felt that Frazer was gunning for Michael's job.
21: Frazer's contract is extended. Anneke and Michael's contract comes to an end about halfway through a serial (The Faceless Ones). Anneke is offered an extension. Michael is not. Anneke quits in solidarity with Michael.
22: Next serial (Evil of the Daleks) introduces Polly's replacement, Victoria, and at this point the behind the scenes situation seems to return to normal.
Absolutely baffling period of television.