Of all of the unexplained enigmas, in Doctor Who. Original companion and family member; Susan – is perhaps one of the biggest.

Was she infact – the Doctor’s ‘real’ granddaughter? Or, did she just use this title for some other reason? Was it an inherited title, from their Coalhill School exploits, in An Unearthly Child?

What is clear, about the young (academically gifted) Time Lord, was that – from a character perspective; she was pretty much forgotten about from the off. With Susan’s teachers; Ian & Barbara – taking centre-stage.

Indeed, Susan seemed simply to be a plot-device, to get the Coalhill School teachers to the junkyard and into the Tardis to meet the Doctor.

It was no surprise then, when actress Carol-Ann Ford – called it a day – in 1965, due to a lack of decent characterisation from the preceding 2 years. She was written out after the events of The Dalek Invasion Of Earth, having met -and fell in love, with a young freedom fighter; called David.

“I was a very good dancer and had been an acrobat. They told me Susan was going to be an Avengers-type girl – with all the kapow of that – plus she would have telepathic powers. She was going to be able to fly the Tardis, as well as her grandfather and have the most extraordinary wardrobe. None of that happened. All my differentness was cut out. They made me wear horrible little trousers, not even funky jeans. Horrible little flat shoes. I don’t know why they did this to me.” Carol Ann Ford on Susan. 2013

Susan’s history following this point, is unclear. Due in some part, to no more follow-up appearances (or explanations in the show, until the 20th Anniversary episode; The Five Doctors.

This seems strange, considering that Susan was (apparently) the Doctor’s family, which would have place Susan – above all of the other companions, in importance.

It seems in some respects, that some of the ideas coined during William Hartnell’s time, were then; directly or indirectly – written out of the show at later points; due to them conflicting with the evolving mythos the show was building.

Susan, naming the Tardis, herself. The Doctor building the Tardis himself. The pair being time-renegades from the 49th century – amongst others. As the accepted Gallifrey back-lore began to take shape, around the end of season 7. These ideas, were largely abandoned.

Maybe Susan – as a family member of the Doctor, was also written out. It seemed an uncomfortable facet, to the Doctor’s personality. That the Doctor had gone and left his granddaughter in space-and-time somewhere and never seemed bothered, in returning to retrieve; or even visit her.

And when a much older Susan, did make a reappearance in The Five Doctors; alongside Richard Hurndell’s First Doctor. There was no mention of Susan’s life – post Tardis. It was pretty much never mentioned again.

And yet assuming if this was supposed to be an older Carol-Ann Ford, playing a young Susan (rather than an older Susan), then she seemed surprised to be meeting the First Doctor again – as if time had really passed between them. The First Doctor didn’t seem to concerned, to ask how she had been getting on either.

Indeed, at the end of the The Five Doctors, the Doctor leaves – in a version of the Tardis, with Susan. So it can be assumed, that they at least travelled together again, for at least a short while.

Behind this, Ford later confirmed that the producers insisted that Susan should not refer to the Doctor – as her grandfather.

“You will not believe why. They said, ‘We don’t really want people to perceive him as having had sex with someone, to father a child.’ I just screamed with hysterical laughter and said, ‘In that case, I’m not doing it!”.

The script was later changed, due to Ford digging her heels in.

What is clear is that Susan, as a character in the Doctor Who universe; was jinxed from the beginning. As to delve into her background – too readily, would have started to unlock aspects of the Doctor’s own family tree.

Aspects, which for a mysterious travelling Time Lord (whose real name we don’t even know), are pretty much better left, uncovered.