Jemma Redgrave will reprise her role and Aneurin Barnard will join the cast of long-running and ever-popular BBC series “Doctor Who.”

“UNIT returns! Jemma Redgrave returns as Kate Lethbridge-Stewart, and UNIT, the long-running organisation set on defending the Earth, returns in the next series of #DoctorWho. Aneurin Barnard also joins the series as the mysterious Roger ap Gwilliam,” said a tweet from the official Doctor Who handle.

The BBC said that no further detail is being issued at this stage, when contacted by Variety.

Redgrave has a recurring role in “Doctor Who” as Kate Stewart, head of scientific research at UNIT.

Barnard’s credits include “Peaky Blinders,” “Dunkirk,” “The Goldfinch” and “1899.”

“Doctor Who” began in 1963 and follows the adventures of a Time Lord known as The Doctor, an extraterrestrial being with a human appearance. The Doctor travels the universe in a time-travelling spaceship called the Tardis.

In Oct. 2022, Jodie Whittaker, the 13th Doctor in the series, regenerated, revealing David Tennant, who was the 10th Doctor, as the 14th Doctor.

The next Doctor, played by “Sex Education” star Ncuti Gatwa, will take control of the Tardis after Tennant, with his first episode airing over the festive period in 2023.

“Doctor Who” showrunner Russell T. Davies had said at the time: “If you thought the appearance of David Tennant was a shock, we’ve got plenty more surprises on the way. The path to Ncuti’s 15th Doctor is laden with mystery, horror, robots, puppets, danger and fun. And how is it connected to the return of the wonderful Donna Noble? How, what, why? We’re giving you a year to speculate, and then all hell lets loose.”