Doctor Who’s Russell T Davies explains how shock companion return came about

However, perhaps the biggest moment of all came mid-way through the episode, when the Doctor was flung out into space and found himself freezing to death.

In his dying moments, one thing was able to bring him back, and give him the push he needed to keep on fighting - the appearance of his granddaughter Susan.

Carole Ann Ford's return to play the character, who was first introduced in the show's very first episode, was a huge surprise, as Susan was seen appearing in a vision and telling the Doctor to find her.

Now, showrunner Russell T Davies has explained how Ford's return came about and why it was crucial to include in that moment of the episode.

Speaking on Doctor Who: Unleashed, Davies said: "At that extreme moment in the Doctor’s life where he’s frozen in space and could be dying, I wanted something extraordinary to bring him back. It was a great moment sitting with Juno [Dawson], who wrote that script, to say ‘Please can you put in Susan? Please can Susan appear to him and pull him out of his deep freeze?’

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"She was like, ‘Wow! Will I do that or what?!’ And then along she came. Carole Ann Ford came to the studio. Top secrecy, everything closed down, everyone signing NDAs, brought in on to the TARDIS. And I think Ben directed that beautifully as well."

Meanwhile, Ford also spoke about her return, saying that she thinks it was "fan power", and their determination to find out about where she is now, that made it come to pass.

Ford also said: "Russell and I hadn’t met, and we had both been hoping to meet, and we went to a party. It was the screening of [The] Star Beast. And so we met there, and it was big screams and hugs and, you know, ‘At last we meet’ sort of thing.

"And while we were hugging, Russell said to me, ‘Would you like to come back?’ And I said, ‘Yes, of course I’d like to come back!’ And he said, ‘Well, that’s good, because you’re coming back!’"

We don't yet know whether Ford will be back in the two-part finale, which begins next week with Wish World, but given her instruction to the Doctor to find her, we wouldn't be at all surprised to see her pop up once more.

Doctor Who continues on Saturday 24th May, with new episodes available from 8am on Saturdays on BBC iPlayer in the UK and later the same day on BBC One. The series is available on Disney+ outside of the UK.

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