Doctor Who: BBC Centenary Special Trailer Breakdown - 11 Things You Must See

This is arguably the big one. Classic '80s companion Tegan Jovanka returns!

Inhabiting the TARDIS from Logopolis to Resurrection of the Daleks, air stewardess Tegan travelled largely with the Fifth Doctor, most of the time in hope of returning to Heathrow Airport. Tegan left the TARDIS after a confrontation with the Daleks where she simply leaves the Doctor because she is tired of the violence and death that follows along.

Resurrection is one of the bloodiest Who episodes, so we can't blame you, Tegan.

In her time aboard the TARDIS, Tegan has encountered every major foe of the Doctor's so a possible rematch with the Daleks and Cybermen could be interesting, especially after the pain she's been apart of over the years.

Of course her role in the story is unknown, but we see her dwelling on not having heard from the Doctor since departing the TARDIS, before later on raining hell with a machine gun on an unseen foe.

This return seems similar to fan classic Sarah Jane Smith coming back during the RTD years, so we'll have to see how worthwhile this is.

But Tegan isn't alone...