Before Doctor Who, Peter Capaldi Played An Eerily Similar Doctor In A Box Office Hit

The revived "Doctor Who" has mostly cast young (or young-ish) actors for its lead role as the Doctor. The benefit of this approach is that the young actor feels fresh to the audience; for instance, Matt Smith was almost completely unknown before being cast as the 11th Doctor, so fans didn't have any baggage from his previous roles affecting their judgment of him.

But fans having a pre-existing relationship with the new actor playing the Doctor isn't necessarily a bad thing. When Peter Capaldi was cast as the 12th Doctor, he was already known for a dozen other memorable roles, a couple of which even happened within the "Doctor Who" universe. On top of that, he had already played a doctor in "World War Z," specifically one who works for the World Health Organization. That's correct: Before Capaldi starred in "Doctor Who," he portrayed a doctor for W.H.O.

Making this even more interesting is the fact the character's never given an official name. He's listed in the credits as "W.H.O. Doctor," causing a type of confusion in viewers that's similar to what "Doctor Who" characters must feel when the Doctor first introduces himself. "World War Z" was released in June 2013, and Capaldi was officially announced as the 12th Doctor the following August; some fans even speculate that Capaldi's credit in the zombie movie was intended as a subtle hint to Whovians, although it's far more likely that it's all a coincidence.

Caution: spoilers for "World War Z" to follow. 

Although most fans point to the doctor connection between these two Capaldi projects, it's also worth noting that "World War Z" wraps up its story in a way that feels awfully similar to the sort of trick "Doctor Who" would pull. "World War Z," of course, centers on a zombie apocalypse, and in the movie's final act, Brad Pitt's lead character, Gerry Lane, hypothesizes (and then proves) the zombies ignore terminally ill people. As such, he and the other uninfected survivors at the W.H.O. facility where the climax takes place (Capaldi's doctor included) inject themselves with a deadly-but-curable pathogen shortly before they know they'll have to deal with zombies. There's even a shot where Pitt's character is triumphantly walking through a zombie horde, untouched by all of them, that feels like something we'd see the Doctor do at the end of a particularly spooky "Doctor Who" two-parter.

For Capaldi's character specifically, there's a sequence where he sees the other characters are trying to escape a confined area filled with zombies. Capaldi's doctor has to choose between the pragmatic choice — refusing to open the doors and dooming the characters inside while ensuring the rest of the facility's safety — or the idealistic choice, which is risking everything just to save some people he only met 10 minutes ago. Naturally, he makes the ideal choice and he pulls it off with no casualties just in the nick of time. It's a very Doctor-y moment for this non-Doctor, er, doctor.

Outside of "World War Z," Capaldi was still a well-established actor in 2013. He was most famous for his role in the political sitcom "The Thick of It" as the very foul-mouthed Malcolm Tucker. This character was so profane that it was a running joke in the "Doctor Who" fandom that the revival's eighth season would be moved up from TV-PG to TV-MA now that Capaldi was on board.

For most Whovians in 2013, the big question was about how the show would address the other Capaldi appearance in the "Doctor Who" universe in season 4's "The Fires of Pompeii." There, Capaldi played Caecilius, a Pompeiian family man who interacted heavily with the 10th Doctor. It was a role that was memorable enough that it sort of needed to be addressed by the 12th Doctor at some point. And sure enough it was: Season 9's "The Girl Who Died" established the Doctor had subconsciously chosen Caecilius's face during regeneration as a way to remind himself to save innocent lives regardless of what the rules say. It was a moment that provided yet another insight into the strangeness of regeneration, a moment that the Disney-era "Doctor Who" season 2 finale was seemingly drawing from.

But the most hard-hitting Capaldi performance was in season 3 of the "Doctor Who" spin-off series "Torchwood," where he plays the government secretary John Frobisher. The character's storyline is so absurdly dark and well-acted that it's jarring to think it happened in the same universe as the Abzorbaloff. If Capaldi's Doctor had seen what happened with Capaldi's Frobisher, he would've been shaken to his core.