Doctor Who star Karen Gillan has been feeding her replacement on the show information about co-star Matt Smith.
Former Emmerdale actress Jenna-Louise Coleman, 26, will be the new assistant after Gillan’s character Amy leaves at the end of this series.
Gillan 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.
"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. I didn't want to plant any preconceptions in her head."
Jenna has been well receieved by the cast, with Smith, 29, praising her ability to fit in with the style of the show: "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, despite her popularity with the fans, has decided that she will not be appearing in next year’s 50th anniversary special.
She said: "I decided there'd be no cameo returns after I leave. 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."
Smith said of the anniversary show: "We want to make it as big and bold and as brilliant as we can because, we hope, it can be one of the monumental bits of TV history. But I doubt there'll be a regeneration..."
Gillan, who has previously admitted stealing a pair of binoculars from the Doctor Who set as a souvenir, said: "Arthur (Darvill) and I actually got the same leaving present, which was two massive pictures of ourselves. It's awkward because I don't know what to do with it. It kind of dominates a room."