'Who', 'Wars' stars make 'Doctors' cameos
Doctor Who star Baker played the sixth incarnation of the Time Lord between 1984 and 1986, while Bulloch is most famed for his role as faceless enforcer Boba Fett in the Star Wars franchise.
The pair will play two foolish old men, Charles Dillon (Baker) and Victor Hendon (Bulloch), who decide it is time to settle a long-running feud over how Victor treated Charles' sister Betty when the two were married.
After Victor announces his intent to re-marry Betty, a disgusted Charles challenges Victor to fight a fencing duel - to the death.
"We've been very lucky to cast these two fantastic and well-known actors for Doctors," said series producer Beverley Dartnall. "It's quite a treat and gives a true sci-fi angle to the episode."