Karen Gillan's requirements for a return to "Doctor Who" are simple: She'll do it if both of her previous co-stars — Matt Smith (who plays the Eleventh Doctor) and Arthur Darvill (who portrays Rory Williams) — join her. Her terms are simply stated, but the possibility of all three returning might be more difficult than it sounds. Smith is currently starring in a "Game of Thrones" spin-off called "House of the Dragon," and Darvill recently wrapped a five-year run on "DC's Legends of Tomorrow" as Rip Hunter.
That's not to mention the story hurdles such a reunion of their characters would require. "Doctor Who" isn't above a light retcon here and there, and it thrives on reintroducing characters that fans have otherwise written off to the annals of history. But Gillan's and Darvill's roles weren't just dropped off — they were given a concrete happy ending and a pair of gravestones. Even though time is a laughable concept for the Doctor and his companions, this particular situation is inarguably a tricky one to renegotiate.
That's not to say such a reentry would be unwelcome, however. Amy Pond (Gillan's role) and Rory Williams are some of the most beloved companions to ever grace the Doctor's adventure. Should it come to pass that a blue moon grants the trio's unified return, there's no doubt that fans would flock to the news en masse in the same way that they're already reveling in the news about a return for David Tennant and Catherine Tate as part of the 60th-anniversary special.
