Doctor Who explains why the Doctor's old face returned

We've had some clues, especially after the Doctor reunited with Catherine Tate's Donna Noble in The Star Beast. But now we've finally got some answers!

In The Giggle, the last of the specials, the pair faced one of the Doctor's oldest enemies, The Toymaker, played by Neil Patrick Harris. With the world driven mad, the Doctor and Donna are taunted by the menacing villain.

As the pair attempt to figure out what's happening, Donna references the return of Melanie Bush (Bonnie Langford) into the Doctor's life, asking why he's never mentioned her before.

She adds that he never stops, telling him: "Maybe that's why your old face came back. You're wearing yourself out.”

Previous episode The Star Beast had seen Donna implore the Doctor not to leave her behind and go whizzing off into the universe again, suggesting: "You could visit with my family. We could do outrageous things like have tea, and dinner, and a laugh.

"You've been given a second chance – you can do things different this time. So why don't you do something completely new and have some friends?"

The Giggle delivered an unprecedented twist, with the Fourteenth Doctor appearing to meet his end, only to experience a "bi-generation" and split into two, with the Fifteenth Doctor existing as a separate being.

With two Doctors now co-existing and the universe safe in Fifteen's capable hands, the Fourteenth Doctor was finally able to take a well-earned break, opting to remain on Earth with Donna and the Noble family.

"I worked out what happened. You changed your face – and then you found me," Donna explained. "D’you know why? To come home.”

“I fought all those battles for all those years..." the Doctor reflected. "...And now I know what for. This. I’ve never been so happy in my life.”

Still, with his own TARDIS, it seems the Fourteenth Doctor won't remain entirely grounded, even taking Rose (Yasmin Finney) and old friend Mel (Bonnie Langford) on an adventure or two...

Doctor Who will return for The Church on Ruby Road on BBC One at 5:55pm on Christmas Day.

Previous episodes are available on BBC iPlayer and on BritBox – you can sign up for a 7-day free trial here.

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