Why Susan Foreman Should Never Return To Doctor Who - And Nor Should Several Other Sixties Companions

I read recently that Peter Capaldi would like Carole Ann Ford to return as the Doctor's granddaughter, Susan Foreman.

However fan pleasing this would be, I believe this is wrong.

Time-travel can be horribly wibbly-wobbly and timey-wimey and complicated, but there is one principle established in Pyramids of Mars, where Sarah Jane Smith notes that they know that Sutekh didn't destroy the Earth in 1911, and the Doctor responds by taking her to 1980 to see the devastated Earth. Their failure to stop Sutekh would create a new timeline in which Sarah was never born. That wouldn't affect her on one level, as her birth was an event in her personal past, but would no longer be an event in the new timeline. If Sutekh won then she would have to explain to various aliens why she was born in 1950ish despite humanity being wiped out about 40 years before her birth.

One fixed point in time was Adelaide Brooke's death in The Waters of Mars - and she was driven to become an astronaut by the events of The Stolen Earth/Journey's End. But in Victory of the Daleks, the Doctor is surprised that Amy Pond cannot remember those events - which implies that there is a new timeline in which the Davros never proceeded with his Reality Bomb plan. In this new timeline:

• Davros wasn't killed in the destruction of the Crucible, as it was never destroyed - he is still out there somewhere.
• Dalek Caan wasn't killed
• The Void didn't collapse, so the events of The Next Doctor - including the Cyberking - never happened
• Adelaide's parents weren't killed
• Adelaide wasn't inspired to become an astronaut
• The future of humanity among the stars which the Doctor told Adelaide about didn't happen

One of the key Doctor Who adventures was Genesis of the Daleks, where the Doctor manages to delay the Daleks' development. That means a new timeline was created in which the previous Dalek adventures - The Daleks, The Dalek Invasion of Earth, The Chase, The Daleks' Master Plan, The Power of the Daleks, The Evil of the Daleks, Day of the Daleks, Frontier in Space, Planet of the Daleks, Death to the Daleks - never happened.

Now, from the Doctor's perspective, these are parts of his personal past. But they are no longer events in the current timeline.

Think about that for a moment. Steven Taylor only escaped from the Mechanoids because the Doctor and his companions (Ian Chesterton, Barbara Wright and Vicki) arrived there fleeing the Daleks in The Chase. The Doctor can remember Steven's adventures from there up to The Savages, but in the current timeline these events were altered due to Steven's absence. From the universe's perspective, the Doctor, Ian, Barbara and Vicki never arrived and never met Steven. Also note that Ian and Barbara leave for London, 1965, in a Dalek time machine. The Doctor and Vicki see them leave, and from Ian and Barbara's perspective, they arrive in London.

But as far as the universe is concerned....

Well, if the Daleks' development was delayed, then the current timeline is one where the events of The Chase never happened, and - although this contradicts The Day of the Doctor and Sarah's comments in Death of the Doctor - from the universe's perspective, Ian and Barbara never returned and are just a couple of schoolteachers who went missing 52 years ago, with a cold crime squad maybe one day deciding to investigate.

The Daleks' Master Plan - well, from the Doctor's perspective, Katarina was killed (and the same is true from her perspective), but if the current timeline is one where this adventure never happened, then her death is no longer an event in the universe. Doesn't mean she's alive - she just went missing from Troy at the end of The Myth Makers as far as the universe is concerned.

Victoria Waterfield's debut was The Evil of the Daleks. Now, this is where it gets complicated. There is a Victoria who travelled with the Doctor and Jamie McCrimmon, whom he will remember. But if he went back to see Frank and Maggie Harris from Fury of the Deep and asked to see Victoria, they wouldn't have a clue who they were talking about. If The Evil of the Daleks never happened, then the Doctor could travel back to a time after 1866, meet Victoria (who would not know who he was), her father and Theodore Maxtible, and see how their continuing time-travel experiments using mirrors and static electricity were going (or rather, failing to go).

And what about The Dalek Invasion of Earth? What went through the Doctor's mind as the Time Lord on Skaro handed him the Time Ring and sent him on his mission? Did he realise that his mission would necessarily mean that his previous encounters with the Daleks would no longer have happened due to the timeline changing, and the cost to him at a family level?

Due to the rewriting of the timeline, there is no apocalyptic post-invasion 22nd century Earth for the Doctor to travel to to see Susan. The Dalek invasion - and its consequences - were removed from the timeline. From the universe's perspective, Susan no longer exists.

And that is the cost to the Doctor of the Time War - permanent separation from his grand-daughter, getting on with her life in a world that doesn't exist.