Peter Capaldi's Doctor Who will not be hosting a temporary companion on the Tardis for the show's Christmas special, according to sources on the show.
Radio Times reports that the currently untitled episode will instead bring back Nardole, played by Matt Lucas, who previously appeared as River Song's former assistant.
Nardole, who has already been confirmed to appear in the upcoming series 10, was last seen on the show as a robot with Lucas' head attached in last year's Christmas special, 'The Husbands of River Song'.
It is also believed that another guest character will be portrayed by Canadian actor Justin Chatwin [War of the Worlds, Shameless], who is said to be playing a "superhero character".
"The Doctor won't have a temprary companion this Christmas and essentially that space will be taken by Nardole," a source told Radio Times. "He's not a companion as such but it's not as if he doesn't play a similar role."
Chatwin tweeted about his "last day" at BBC studios on 30 September, two weeks after apparently travelling to Wales (Doctor Who is mostly filmed at the studio's set in Cardiff).
Speaking to fans in April, Peter Capaldi revealed that the tenth series of the show will air in April, along with the announcement that he would be joined by new companion Bill, played by Pearl Mackie.
Capaldi had also hinted that Jenna Coleman may return to the show after leaving in series nine, saying that they had filmed something together post-season nine.