"Doctor Who": Peter Capaldi is revealed as the new Doctor Peter Capaldi will play the 12th version of the Doctor. Genaro Molina / Los Angeles Times It's official: Peter Capaldi has been announced as the new Doctor. The 55-year-old Scottish actor is by no means a "Doctor Who" discovery along the lines of the most recent Time Lord, Matt Smith. In fact, the new Doctor already has his own following from the British political satire "The Thick of It" and the big-screen spinoff "In the Loop." In both the series and the film, Capaldi played a foul-mouthed political spin doctor named Malcolm Tucker. But fans worrying that this casting means the Doctor is about to go down an adults-only path should relax. As Capaldi reassured fans just moments after the announcement of his casting: "Malcolm has been banished from the mirror by this new Doctor, who wouldn't put up with Malcolm's language." The big reveal was made during a live telecast on Sunday hosted by British TV personality Zoe Ball. The fifth Doctor, Peter Davison, was on hand to talk a bit about what's to come, not just for Capaldi, but also for the departing Smith. "In a way, it's the longest job in television," Davison said. It's a whirlwind time when you're doing it, but then it continues after you've left. Capaldi is no stranger to the "Doctor Who" universe. He appeared in the 2008 episode "The Fires of Pompeii" alongside the 10th Doctor, David Tennant. And he's been a lifelong fan. To prove it, Ball displayed a fan letter a 15-year-old Capaldi had written to the Radio Times to express how much he loved the show. As Capaldi explained, "I haven't played Doctor Who since I was 9." He was filming the BBC's adaptation of "The Three Musketeers" in Prague when he got the call, which his agent answered by saying, "Hello, Doctor." To prepare, Capaldi said he downloaded old scripts from the Internet and practiced performing them. But he said that current executive producer Steven Moffat has already written some scenes featuring the new iteration of the Doctor. Though Moffat played the casting of Capaldi close to the vest, he did drop hints about which direction he was planning to go when talking to Hero Complex last month, saying, "I was thinking someone in their 40s, probably... Most of the people we saw in their 20s were no good at all, or were good actors but they weren't right for it." Smith, who has played the 11th incarnation of the Doctor since 2009, announced earlier this year that he was planning to leave the role after the 50th anniversary special to be aired in November 2013 and the Christmas special to air the following month. It was during Smith's three-season run as the Doctor that the series saw a huge surge of popularity in the United States, where it had largely been a cult show at best for most of its 50 years. The 2012 season premiere of the series grabbed BBC America's highest rating ever, with 1.55 million viewers tuning in. That doesn't take into account the series" already large following in the U.K. Following this announcement, Smith still has one more go-round as the Doctor since the Christmas special doesn't film until September. To close out the live broadcast, Smith sent a videotaped message from Los Angeles to the new Doctor: "I just want to wish my successor all the best and say good luck and good on you for getting it.... It's going to be a thrill.