Steven Moffat hopes to keep spoilers to a minimum and keep the nature and character of the new Doctor Who companion – to be played by Jenna-Louise Coleman – a mystery until she’s introduced in the Christmas Special.
Responding to a question about when we’ll learn the identity of the new companion during a Digital Spy interview, Moffat replied, “Christmas! But don't expect to learn everything! We've got a good story and there are some proper legitimate surprises in it. I'm excited by it. I think we're going to do some fun stuff.”
Although he admits that keeping a lid on the mystery may be difficult: “We can't really contain everything, because people will crawl all over us with cameras and sneak views of scripts and call-sheets. Something will get out. But we've been fairly sly, so let's wait and see.
"Again, a lot of the audience that I talk to specifically avoid any spoilers and I'm absolutely certain they have a better experience of the show. As I've always said, if I could make it on the dark side of the moon, I would, but you can't do these things.
"i got pilloried by somebody at some deep level of naivety about the industry - they were angry that I'd revealed the fact that Amy and Rory were even going to leave! But y'know, actor's agents really do have to advertise their client's availability – I had no choice but to announce they were going to leave. But in an ideal world, you wouldn't even do that.”