Tom Hiddleston opened the Zurich Film Festival on Sept. 24 with "Tenzing" and a Golden Eye Award, and used the stage to recall two very different mountains of his career: the Marvel Cinematic Universe and Mount Everest itself.

Hiddleston played Loki in "Thor," only the second film of a franchise that now seems unstoppable. He described those early Marvel days as "larger than life" — a shift from working with British auteur Joanna Hogg on "Unrelated" and "Archipelago," though not an artistic whiplash. Both Hogg's work and Loki, he noted, dealt with family issues.

"The difference [with Marvel] was in the scale of the resources, the size of the crews, the size of the sets," Hiddleston said. "It was so larger than life."

The actor went on to play Loki in seven movies and two seasons of the series "Loki." His strongest memories of the first shoot center on Chris Hemsworth, his on-screen brother.

"We were immediately bonded," he said. "It was a shared excitement about being invited to make a film like this. Marvel Studios had made one film at that time, which was 'Iron Man,' which we both loved, and we were being directed by Kenneth Branagh, Anthony Hopkins was playing our father, Rene Russo was playing our mother, and we had extraordinary resources. We had an amazing, brilliant creative stunt department where we would train for sequences of dizzying choreography. We both loved movement and these opportunities."

He called the friendship "very vivid, happy, immediate, fast," saying both actors felt like "the two luckiest guys in the world" given "this extraordinary opportunity to play these magnificent characters and bring them to life for the first time."

Of the film's scale, he said: "It was a different dimension." The scenes were "full of turbulence, turmoil, soul and emotion."

Hiddleston thanked the late screenwriter Don Payne for developing Loki's "complex" backstory, and remembered an early conversation with Marvel Studios president Kevin Feige, who told him "Thor" wasn't "the only film you're going to be in." Feige laid out the plan: "Iron Man," then "Thor," then "Captain America," then "The Avengers" — and, as Feige put it, "In the first edition of the first 'Avengers' comic, from 1967, the villain is Loki, and we want you to be the villain."

"I never expected to be playing the character for this long," Hiddleston said. "But he's a brilliant character of such depth and dimension. I knew where we had started in 'Thor,' and I wanted to get back to his capacity for love and his belonging to his family. I wanted to somehow find a way of completing that arc. It's a long journey."

He declined to discuss "Avengers: Doomsday" beyond confirming "it is coming." The film premieres Dec. 18.

The conversation then turned to Jennifer Peedom's "Tenzing," which chronicles the first ascent of Mount Everest. Hiddleston plays Edmund Hillary opposite Genden Phuntsok as Tenzing Norgay, with Willem Dafoe, Caitríona Balfe and Tenzin Jigmey also in the cast of the Apple TV film.

"I've been compelled by Everest for as long as I can remember," he said. What drew him in, he explained, was the film's premise: "to put Tenzing Norgay at the center of his own story, to reframe that narrative from a different perspective and bring him into the foreground." Peedom sent him the screenplay three years ago with what he called a beautiful letter.

Hiddleston also praised Peedom's 2015 documentary "Sherpa," which examined Sherpa culture and the exploitation of local climbers by wealthy Westerners. After reading the script, watching the documentary and meeting the director, he signed on — and then climbed to Everest's base camp alongside Peedom, Phuntsok and a high-altitude medical specialist. The experience, he said, connected him to both the physicality and the spirituality of the role.

"I love that this film really reveals the deeply spiritual relationship that Tenzing had with the mountain, not a mountain to be conquered, but a goddess to be revered, a mother into whose lap he might climb," he said.

Of Hillary and Norgay's 1953 achievement, he added: "They achieved the impossible, like stepping on the moon. After that, their lives were changed forever; summiting Everest became possible, and thousands and thousands of people have done it since."

The Zurich Film Festival runs through Oct. 4, with "Tenzing" leading a lineup that now carries Hiddleston's Golden Eye imprimatur.