10 Doctor Who Mysteries With The Worst Possible Answers

5. Who Is The Doctor's Daughter?

The story goes that Georgia Moffett, daughter of Fifth Doctor actor Peter Davison, originally auditioned for a role in The Unicorn and the Wasp. Instead, she was cast as Jenny in The Doctor's Daughter because it was marketing gold for the series.

Her role was first broken a few months before the episode aired, giving fans enough time for lots of feverish speculation. Were we finally about to meet Susan's mother?

The hype train for The Doctor's Daughter came to a screeching halt when, before the opening credits had even rolled, we learned that Jenny was cloned from the Tenth Doctor's DNA. Was that it? Well, yeah, pretty much. Answering such a potentially huge mystery in a matter of minutes in the episode teaser was such a bizarre decision, and speaks to how The Doctor's Daughter was primarily designed to give a mid-series ratings bump, rather than actually having anything important to say about the Doctor's family.

Imagine how much more interesting The Doctor's Daughter would've been if her identity had been more ambiguous to begin with? Instead, Russell T Davies and Stephen Greenhorn were more interested in building hype for the episode rather than delivering an intriguing mystery within it.

RTD later pulled a similar trick with The Next Doctor, though he did at least manage to drag out the mystery beyond the opening titles.