Peter Capaldi could end his time on
Doctor Who with a rare double Doctor episode also featuring the Time Lord's original incarnation.
David Bradley is set to reprise his role as the First Doctor, teaming up with Capaldi's Twelfth Doctor as he departs in this year's Christmas special, according to reports.
The pair are said to be tackling a vital mission to save their home planet of Gallifrey by moving it to another dimension, as first referred to in 50th anniversary special The Day of the Doctor.
The First Doctor was originally played by the late William Hartnell, with the role taken over by Richard Hurndall for the 1983 multi-Doctor adventure The Five Doctors.
Harry Potter star Bradley, 73, played the part in 2013 in Doctor Who 50th anniversary documentary drama An Adventure in Space and Time, in which he shared a brief moment and a smile with Matt Smith's Eleventh Doctor.
told the Mirror: “David was convincing as Hartnell, it’s exciting he’s back. Four years ago it took all the previous Doctors to save Gallifrey, so maybe some of the others will also pop up in Capaldi’s swansong.
“It’s great that the First Doctor will be there to help out during those all-important regeneration moments.”
RadioTimes.com contacted the BBC who declined to comment on the story.