Doctor Who's outgoing star Karen Gillan has revealed that she has been been feeding her replacement on the show nuggets of information about co-star Matt Smith.
Karen Gillan and Arthur Darvill in their own little spin-off prequel Pond Life - Watch the first episode below...
Former Emmerdale actress Jenna-Louise Coleman, 26, joins the sci-fi drama as the Time Lord's new assistant after Karen, 24, who plays Amy Pond, bows out.
Gillan, who makes her last appearance in next month's BBC1 series, told the Radio Times: "I've met Jenna and we get on really well. And I've been texting her bits and bobs about Matt, but what I wrote is a secret.
Joanna-Louise Coleman in pictures...
Jenna-Louise Coleman
"That's the code of the companion. I didn't offer her any advice though because I want her to have the experience for herself."
Smith, 29, praised his new co-star, telling the magazine: "The show is so much about dealing with Steven (Moffat's) writing, having an instinct for the tone and pace.
"And Jenna nailed that tone of fear and adventure. We did the auditions down in the bowels of the BBC and it was meant to be top secret, which is ridiculous because we'd been going for four hours when we heard a cough behind a partition.
"And there was this security guard with his feet up and we said to him, 'Man, do you know what this is?' And he was like, 'What?' So it wasn't that secret. But I did phone the Daleks in and said, 'I need a favour, boys...'"
Gillan, who is starring in a miniseries about the Time Lord's trusty sidekicks, said that she would not be returning for next year's one-off, 90-minute 50th anniversary special, saying: "I want the impact of the end of the Pond era to remain strong. I don't want to spoil it by coming back a few episodes later to say hello."
WATCH the first episode Pond Life, the online prequel to the new series of Dr Who, below...
