According to Peter Capaldi, the Twelfth Doctor has a lot in store in the upcoming ninth season of "Doctor Who."

"[The Doctor is] throwing himself into life with a newfound hunger for adventure," Capaldi revealed in an interview with Entertainment Weekly. "He's in pursuit of joy and grabbing every thrill that he can along the way. But I sense him running from something, that even he does not yet understand."

This sense of joy will extend to the Doctor's current companion, Clara (Jenna Coleman): "They've suddenly realized that they are the most fortunate people in all of time and space and are hellbent on adventure. Jenna continues to deliver a beautifully nuanced, complex, and funny performance that marks her out as one of the best companions ever." Likewise, he described guest star Maisie Williams ("Game of Thrones") as "a sharp, talented tornado" and revealed she will play a character who "shifts in cosmic ways."

However, as is typical for the space-adventuring Time Lord, this new lease on life won't be smooth sailing all the way. "[The two-part premiere] places the Doctor in a conflict that is central to his being, as well as containing some subtle tributes to the '60s, and truly wonderful guest performances."

"There is an epic sweep to this season and I think the villains and monsters reflect that," he continued. "Great new ones, brilliant old ones and some very scary creatures looming in stories with real emotional ambition." Among the returning villains, Michelle Gomez's Missy will also make a comeback, and Capaldi promises, "in the hands of Michelle Gomez, Missy is more magnificently bad than ever before."

As to the photo unveiled in the interview (below), Capaldi teased, "The photo shows the Doctor about to make a mistake that has cataclysmic repercussions."

"Doctor Who" returns to the BBC this fall.