'Thor: Ragnarok' Spoilers, Plot News: Cate Blanchett's Hela is His Sister?

Chris Hemsworth and the cast of "Thor: Ragnarok" are making the press round a few weeks before the movie's release. During one TV interview, however, a host spoiled one of the key storylines in the Marvel flick.

Cate Blanchett is Hela in "Thor: Ragnarok," which stars Chris Hemsworth.

Hemsworth (Thor) was on an Australian TV show, "The Project," with Mark Ruffalo (Hulk) to talk about "Thor: Ragnarok." The host, however, kept referring to Cate Blanchett's character, Hela, as Thor's sister when it's supposedly a big reveal in the movie.

"You can't say sister," Hemsworth told the host looking quite upset. "You can't give that away."

Ruffalo, on the other hand, looked uncomfortable and wondered if the interview was a live broadcast.

Blanchett's Hela, the Goddess of Death, is the film's big bad. Her story's version in the comic series does point to the character as related to Thor because she's Loki's daughter. This detail shouldn't be quite a shocking revelation to some fans, except that it's a twist in the movie version, which has been altered slightly to fit its narrative.

Hela is the first female villain in the Marvel Cinematic Universe (MCU) whose real intentions will be tackled in the movie. Blanchett shared that she had so much fun playing the character because she could go as insane as she wants.

Meanwhile, early reviews of "Thor: Ragnarok" have been encouraging as critics expressed it's the funniest and most entertaining installment in the franchise. Viewers who saw the advance screenings praised director Taika Waititi for his work and but he confessed that he thought Marvel would fire him in the middle of filming for his crazy ideas.

"Mark Ruffalo would be finished shooting for the day," the director said. "He'd come up to me and he'd be like, 'Why have we not been fired yet? We are doing the most insane stuff in this film, so where's the phone call?'"

"Thor: Ragnarok" will open in theaters Friday, Nov. 3.