Other (Doctor Who)

The Other
Doctor Who character
First appearance	Remembrance of the Daleks (novelisation)
Last appearance	Lungbarrow
Information
Affiliated	Time Lords
Home era	Rassilon Era, the Old Time

The Other is a fictional character in the British science fiction franchise Doctor Who. A legendary figure in Time Lord history, the Other was only alluded to in the television series, but is featured several times in spin-off media based on the programme.

The Other was intended to be part of the backstory of the television series during the Seventh Doctor's tenure and part of script editor Andrew Cartmel's intention now known to fans as the "Cartmel Masterplan" to restore some mystery to the character of the Doctor. Cartmel felt that years of explanations about the Doctor's origins and the Time Lords had removed much of the mystery and strength of the character of the Doctor, and decided to make the Doctor "once again more than a mere chump of a Time Lord". Elements of this effort were liberally scattered through Seasons 25 and 26 of the series, and occasionally included hints about the Doctor's past; for example, in Silver Nemesis, when Ace and the Doctor discuss the creation of validium, the Doctor mentions that it was created by Omega and Rassilon. Ace asks, "And...?" and the Doctor is silent. Cartmel has written that this was meant to indicate that the Doctor was "more than a Time Lord":

... Omega and Rassilon were the founding fathers of the 'Time Lord era' of Gallifrey. They towered above the Time Lords who followed. They were demigods. And Ace's nifty dialogue "And..." coupled with the Doctor's neatly evasive response, are a subtle attempt to say that there was a third presence there in the shadowy days of Gallifrey's creation. In other words, the Doctor was also there. So he's more than a Time Lord. He's one of these half-glimpsed demigods.

...
Wikipedia