Since the very first episode of Doctor Who, Susan Foreman has been an enigma, primarily defined by her relationship to the Doctor as his granddaughter. Throughout the series, particularly in the early episodes with the First Doctor and in later episodes referencing the Doctor’s past, the term “granddaughter” is used repeatedly to describe Susan. This has led many fans to accept this familial connection at face value. However, when examining the evidence within the TV show and movie canon, a compelling case emerges for Susan being not just a granddaughter, but the Doctor’s biological granddaughter.
One of the most significant pieces of evidence is the Doctor’s consistent and repeated references to Susan as his granddaughter. From the First Doctor era to mentions in the revived series, such as in “The Empty Child” and “The Rings of Akhaten,” the Doctor’s language strongly implies a direct familial link. He speaks of her as a granddaughter without any caveats or alternative explanations provided within the televised stories. This consistent terminology across different incarnations of the Doctor lends considerable weight to the idea of a biological relationship.
Furthermore, Susan’s origins and knowledge base align with Gallifreyan culture, the home planet of the Time Lords. She demonstrates understanding of concepts beyond human comprehension, famously stating the need to use five dimensions for mathematics, referencing Time and Space as the fourth and fifth dimensions. This advanced knowledge is indicative of a Time Lord upbringing. Adding to this, the Doctor himself states in “An Unearthly Child” that they were both exiled from their home and would eventually return, heavily implying Susan shares his Gallifreyan origin. The episode “The Name of the Doctor” further solidifies this, depicting Susan alongside the Doctor when he departed Gallifrey in his TARDIS, suggesting she was with him from the very beginning of his travels.
The Doctor’s controversial statement in the 1996 TV movie, claiming to be “half-human on my mother’s side,” introduces a layer of complexity. This is the only instance in the entire televised canon where the Doctor makes such a claim. If taken literally, it could potentially impact Susan’s lineage, making her at least partially human if she is indeed his biological granddaughter. However, this statement is rife with inconsistencies. Neither Romana, the Master, nor any other Time Lords ever allude to the Doctor’s supposed human heritage throughout the series. Moreover, in “The End of Time,” the Time Lords appear to accept the Doctor’s mother as one of their own, which would be highly unusual if she were human and not fully Time Lord.
Several plausible explanations can account for the Doctor’s half-human declaration without dismissing Susan’s Time Lord biology. Firstly, the Doctor’s memory could have been compromised due to the amnesia he experienced, attributed to human anesthetic affecting his post-regeneration state, as depicted in the movie itself. Secondly, in line with River Song’s famous adage, “Rule #1: The Doctor lies,” the Doctor might have simply been fabricating the half-human detail for his own amusement or to manipulate the situation. In either of these scenarios, Susan remains a full Time Lady, directly descended from the Doctor’s Time Lord lineage.
Even if we entertain the possibility that the Doctor’s half-human claim is truthful, it doesn’t negate the strong evidence for Susan being his biological granddaughter. In this case, Susan would be at least one-quarter human and one-quarter Time Lord, inheriting her Time Lord traits and Gallifreyan origins through her paternal lineage. The remaining aspects of her genealogy would depend on the specific nature of the Doctor’s child and their partner – whether they were human, Time Lord, or a hybrid themselves.
In conclusion, while the Doctor Who canon presents some ambiguities, particularly with the half-human statement, the overwhelming evidence within the TV series and movie strongly supports the interpretation of Susan Foreman as the Doctor’s biological granddaughter and a Time Lady. The consistent use of familial language, Susan’s Gallifreyan knowledge, and her presence with the Doctor during his departure from Gallifrey all contribute to this compelling conclusion, making Susan Foreman a vital and biologically connected part of the Doctor’s enduring legacy.
