10 Doctor Who Moments Deeper Than You Think

In Series 3 opener Smith and Jones, trainee doctor Martha Jones asks her patient "John Smith" if he has a brother. To which the Tenth Doctor replies, "Nope, not any more".

Fast-forward to The Sound of Drums, and while discussing what went wrong between the Doctor and the Master, Martha says: "I thought you were gonna say he was your secret brother or something."

There's an awkward silence before the Doctor derisively replies, "You've been watching too much TV."

Not only was this Russell T Davies' response to a popular fan theory he found quite silly, it also links back to the two times that Doctor Who tried to make the Doctor and the Master secret brothers.

Before the sad death of Roger Delgado, a potential final confrontation between the Third Doctor and the Master would've revealed one of two things: either the Master was the embodiment of the Doctor's darkest impulses; or, he was his evil brother.

Then, in Planet of Fire, when the Master is about to be killed, he implores the Fifth Doctor to "Show mercy to your own-" before being cut off. Director Fiona Cumming asked producer John Nathan-Turner for clarification, and was told that the line would've ended with "brother."

Clearly, Doctor Who writers in the '70s and '80s watched too much TV!