TORONTO, ONTARIO. Deeply immersed in character, many actors are uncomfortable having even brief conversations when reporters drop by their sets. This goes double or triple when the thespians are playing dark roles, twisty roles, roles that require tapping into wounded places in their psyches.

It's mid-March 2014 on the set of Guillermo del Toro's "Crimson Peak" and Jessica Chastain is wrapping a candid conversation with a dozen reporters by giving a concert in her trailer. 

The keyboard sitting against one wall in the trailer spawns a question about whether or not Chastain's character, sporting the impeccably Victorian name of Lady Lucille Sharpe, plays the piano, but it's Chastain who volunteers to tickle the synthetic ivories. 

"Have you guys heard the lullaby?" Chastain asks without hesitation. We have not, of course. "Crimson Peak" is over a year away from an October 16, 2015 release date and neither images nor a trailer have been released yet. 

"Do you guys want to hear it?" She asks, even more eagerly.

A minute later after we've all rotated and gathered around Chastain and uncertainty sets in.

"You guys, I get really nervous. I'm going to mess up, probably," she warns us.

She tunes a little.

"And I haven't played the song in a long time!" she adds, before launching into the simple, spare, lovely lullaby, composed by Fernando Velazquez. [I'd love to share the audio with you, but music approvals being what they are, it's just not possible. Sorry.]

"My hands are shaking!" she says, two-thirds of the way through, producing a rare moment in which journalists on a set visit are inclined to give positive reenforcement to an actress with a pair of Oscar nominations.

Chastain's nervousness isn't all that surprising if you realize that the skill she's demonstrating for us isn't actually on her resume. 

"I've never played the piano before," she says. "And Guillermo in November was like, 'I want you to play the piano and you have to start taking lessons.' So it's been a deal."

Jessica Chastain and Guillermo del Toro

This isn't unusual for Chastain, who also trained to play the bass for the del Toro-produced "Mama."

And, actually, the piano-rehearsing appears to be the most innocuous part of her training process.

As the trailers for "Crimson Peak" have already indicated, Lucille will be one of Chastain's darker roles. Lucille and brother Thomas have a very, very close relationship and when Thomas weds a young American author named Edith (Mia Wasikowska), Lucille takes a very intense interest in her new sister-in-law.

This was the choice that Chastain made.

"When I sent the screenplay to Jessica, I didn't send it with any part in mind," del Toro says. "But everybody was assuming she was going to read Edith. And she read the part, and she said, 'I want to play Lucille,' which is the antagonist. And I thought, 'Smart girl.'"

Chastain explains, "[W]hen he sent me this, I think I gravitated towards Lucille because as an actress I always want to play the roles that I haven't played before and I always try to go as different from me as possible. I mean of anything I've ever played, she's the most different."

And speaking of differences, for the first three weeks of production on "Crimson Peak," Chastain was flying back and forth between shooting days on J.C. Chandor's "Most Violent Year," which meant the day-to-day whiplash of going from 1980s New Jersey Lady MacBeth to 19th Century British... Well, how do we describe what Lucille is?

"She had a very difficult life that she has come from," Chastain says of Lucille. "And so all she's trying to do is preserved her happiness because she's a woman who's had little happiness in her life.  So I don't see her as the antagonist. I mean yes, of course, in the grand scheme of things she is, but I'm still playing her so I can't see her that way."

So while the keyboard is one of the focuses for attention in Chastain's trailer, most of the decorations tend toward the twisted and macabre. The walls are festooned with mood boards, the most disturbing focusing on sibling relationships -- twins, gestation studies. She also has black-and-white images of hardscrabble miners, reflecting the mining background of the Sharpe estate.

On her shelves, the books include something called "Death Poems" and a biography of Elizabeth Bathory.

Next to the TV is a DVD of "What Ever Happened to Baby Jane?"

And she's excited by her research.

"There's a Hungarian Countess Elizabeth who killed over 600 women and she's incredible," Chastain gushes. "She bathed in their blood.  And she would kill them, sometimes she'd bite them to death.  he would throw them out in the snow, pour water on them and keep doing it until they froze to death. She would stick pins up their nails. She had a contraption made that was like a barrel that she would get these young girls in and then they'd crank it closed, it has spikes on it and she'd bathe in the blood that would drip down. I mean she was so disturbing. She was found guilty but all they did was basically wall her up in her house. So they didn't put her to death."

Chastain's passionate investment in the role has dove-tailed with del Toro's own process, which includes giving his actors lengthy biographies for their characters, including secrets that they have to keep from the other actors around them.

"You never get things like this from a director," Chastain gushes. "I'm used to doing all this work on my own. And when he sent me this, I'll show you how elaborate it is, it's such a dream come true for an actress to get to get this."

She pulls out a thick binder that looks almost porcupine-esque with its protrusions of multi-colored post-its. The information provided by del Toro includes Lucille's primary psychological traits, her fears, her insecurities, but also her favorite smells ("good tobacco") and tastes ("very bitter chocolate"), things that probably won't be visible in the movie, but will still inform the character.

"This is something that I always do as a character, but the problem is when the director is not involved then there's a secret," Chastain says. "When I'm playing something sometimes the director is like why is she doing that or they don't understand the world that I'm coming from. But to have this and have a starting off point and have the secrets that have happened to Lucille from basically he's written off her whole life up to the beginning of the movie, when he sees me play a scene now he understands oh that is because of this and because where she's coming from or it's because she doesn't want to leave the house or she doesn't like germs."

But really what drives the character is her love for her brother, which sounds sweet, right up until it doesn't.

I think they've suffered a lot and the only happiness they've ever had in their life was each other," Chastain says. "It's the safety for her, like for her home is her safety and her brother is her safety. I mean I'm sure it can be suffocating. It's very codependent."

She adds, "[I]f someone is your everything in your life and the only reason for happiness you're going to be possessive of it because to lose that is to die. So I don't see that as a negative thing here because any negative quality she has everything comes from love."

This would be getting disturbing except that Chastain says everything with a soft smile as she looks encouragingly down at her three-legged dog Chaplin, who interrupts any pensive silence with a loud gnawing on a chew toy.

It comes back to that idea that actors playing less-than-savory characters can never look at them that way and, indeed, Chastain's reaction as she finishes playing for us says everything about her mindset. 

"It's very sad, right? It's Lucille's lullaby. See, so I love her even though she's misguided."

"Crimson Peak" opens on October 16, 2015.



A long-time member of the TCA Board and a longer-time blogger of "American Idol," Dan Fienberg writes about TV, except for when he writes about movies or sometimes writes about the Red Sox. But never music. He would sound stupid talking about music.