Actress Mia Wasikowska attends the premiere of "Crimson Peak," at the Loews Lincoln Square, Wednesday, Oct. 14, 2015, in New York.

Wasikowska plays a young woman drawn to the mysterious Sir Thomas Sharpe (played by Tom Hiddleston), who lives in a dark mansion with his sister, the diabolical Lucille (Jessica Chastain).

"I think it's a gothic romance for sure," Wasikowska said. "I think there're elements of a couple of different genres, like horror and drama. So I think [Del Toro] kind of manages to pull them all together."

Actor Tom Hiddleston attends the premiere of "Crimson Peak," at the Loews Lincoln Square, Wednesday, Oct. 14, 2015, in New York.

"The first time I walked onto the set on 'Crimson Peak,'" Hiddleston said Wednesday, "it was like stepping into a fantasy world. It was like stepping through a magic porthole, because this house had been built on three stories and it had become so completely imagined and completely realized that it felt very child-like."

Actress Jessica Chastain attends the premiere of "Crimson Peak," at the Loews Lincoln Square, Wednesday, Oct. 14, 2015, in New York.

"What's really great is, Guillermo had made sure he wrote a character that was really layered and really complex," Chastain said of her "Crimson Peak" role. "And you could understand why they were doing the things that they were doing, and you could see the pattern developing as a child and how she deals with the people around her. And so that makes it easier. But I will say it is much harder -- as an actor, you have to defend every character you play, if they do good things, bad things, whatever. You're there to be their defense attorney."

Actress Emily Coutts attends the premiere of "Crimson Peak," at the Loews Lincoln Square, Wednesday, Oct. 14, 2015, in New York.

"Crimson Peak" stars Jessica Chastain, Tom Hiddleston and Mia Wasikowska pose in front of a window display at the luxury department store Bergdorf Goodman in New York, Oct. 13, 2015. Bergdorf Goodman decorated their windows in a theme inspired by the film.