58-year-old Scottish actress Lindsay Duncan will join David Tennant in the TARDIS, according to a report by the U.K.’s Daily Record that quotes producer Russell T. Davies.
Duncan will play Adelaide — “the Doctor’s most strong-minded companion yet” — in a still-untitled TV special that will follow Easter’s “Planet of the Dead,” starring Tennant and erstwhile Bionic Woman star Michelle Ryan.
“I’m thrilled to be involved in Doctor Who,” Duncan told the Record. “I’ve never done anything like this before and I’m really looking forward to working with David Tennant and the Doctor Who team.”
Duncan’s most recent credits include a role as the first female prime minister of Great Britain in the BBC’s Thatcher, 18 episodes of HBO’s Rome (pictured) and two appearances on the spy thriller Spooks, better known in the U.S. as MI-5. According to IMDb, she also provided the voice of the Trade Federation protocol droid TC-14 in Star Wars — Episode I: The Phantom Menace.
There’s no word yet on whether Adelaide will remain in the TARDIS for the two specials that will follow her debut and lead into the 2010 season, which will see Tennant depart as the Doctor regenerates into an 11th incarnation to be played by 26-year-old Matt Smith.