Doctor Who writer Toby Whithouse has dropped hints about the next series.
The sci-fi drama's seventh run will see Karen Gillan (Amy Pond) and Arthur Darvill (Rory Williams) depart, with a new companion replacing the pair.
Whithouse, who is expected to write the third episode, told The Hollywood Reporter that he is aware of "some plans for the new companion".
"In terms of the series as a whole.... there are quite a few things I know," he teased. "The one downside of working on Doctor Who is that you know what's coming up."
The Being Human creator agreed that it was time for Matt Smith's Doctor to get a new assistant, adding that the show's companions "have a natural shelf life".
"I know a bit about the new companion, [but] I don't know who they cast," he explained. "Even if I did, if I told you [showrunner] Steven Moffat would come out here and punch me in the neck.
"Steven is one of the cleverest, most inventive people I've ever met in my life, and so you know it is in very safe hands with him. If he makes decisions, the chances are it's for the best - it's the best thing for the show."
The new series of Doctor Who began filming last week in Wales, with Sherlock star Rupert Graves, Harry Potter actor David Bradley and The Fast Show's Mark Williams all cast in guest roles.
The series will return to BBC One in the autumn.
