Doctor Who writer Steven Moffat said it felt “like a miracle” when he saw the show’s new star Jenna-Louise Coleman audition with Matt Smith.
The 25-year-old former Emmerdale actress was revealed yesterday by the BBC as the Time Lord’s new assistant.
Karen Gillan, who plays Amy Pond, is due to leave the BBC adventure this year along with Arthur Darvill, who plays her on-screen husband Rory.
Moffat said Coleman’s partnership with Smith “came to life” during the auditions.
He said: “It always feels like a miracle when you find the right person because we saw a lot of brilliant actresses.
“There was a moment I remember from the second time she came in, and they were auditioning together and they both looked frightened doing a Doctor Who scene, and it just was an instant poster.”
Coleman, who played lesbian Jasmine Thomas in the Yorkshire soap, starts filming in May and will make her first appearance in the Christmas Day special.
Moffat remained tight-lipped about the new series, saying Coleman’s introduction would not be “the usual story”.
He said: “It’s a very, very different way for the Doctor to meet his new friend.”
Fans will see six episodes this year with eight more in 2013 and Moffat revealed Gillan would be written out in the fifth episode of 2012 in a “final encounter” with the weeping angels.
He said: “Not everyone gets out alive and I mean it this time.”