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 unveiled today as the Time Lord's new assistant in the sci-fi show.
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:
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.
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: "Not everyone gets out alive and I mean it this time."
Coleman, from Blackpool, will soon appear as Annie Desmond in Julian Fellowes' new ITV1 Titanic drama.
She said she was "beyond excited" to join the show and "so relieved" to finally be able to tell people she had the job six weeks after finding out: