10 Unanswered Doctor Who Mysteries
4. Did The Doctor Have His Own Family?
This mystery ties into others we will look at later in our list, with several plot points making this idea all the more feasible. The mystery of if The Doctor ever had a wife and children arises from the fact that his first ever companion, Susan, was apparently his granddaughter.
While calling Susan his granddaughter could be explained away as her being adopted rather than a blood relative, a comment from The Doctor during series 2 of the modern series gave this idea extra legs. In the episode titled Fear Her, David Tennant's Doctor casually states to his then companion Rose that he was a father once, a quick little aside that was never acknowledged after.
If it is in fact the case that the Doctor did have children, then the big question becomes who the mother is and when did this happen. River Song seems the most logical option, although how the baby would fit into her already convoluted timeline is enough to make your head spin.
There is also the possibility that Jenny had a child that the Doctor then brought up, but how the Doctor's daughter would have got back to early Gallifrey would be another mystery in itself. The most likely story is that the Doctor fell in love with a Gallifreyan lady and had a family on his home planet, which he lost in the Time War.
Or then again, maybe the Doctor was in female form and had the child himself. Now that would be a twist!