Jan. 27 (UPI) -- Sunday's episode of Doctor Who featured the introduction of the first black Doctor and the return of the long-absent Captain Jack Harkness.
Jodie Whittaker plays the 13th incarnation of the time-traveling Doctor on the sci-fi show.
This weekend's adventure saw her meet a woman named Ruth, played by Jo Martin, who turned out to be a previously unseen regeneration of the Doctor, according to Yahoo News.
As of now, it is unclear how this character will fit into the show's mythology. Also unknown is whether she will appear in future episodes or if this was a one-time-only guest appearance.
Whittaker, who has played the Doctor since 2017, was the first woman to play the role. She is signed on to continue as the Doctor for at least another season.
The latest episode also featured the unexpected return of Captain Jack Harkness, who was played by John Barrowman in previous seasons of Doctor Who and the spin-off, Torchwood.
In an Instagram post, Barrowman called the positive online fan reaction he received "truly overwhelming."
"Let's hope there is more. You never know," he said in a video. "I love all my Whovian fans, all my Torchwood fans. Thank you so much, worldwide. This is the bomb. Captain Jack is back!"