From show creator Graeme Manson (Orphan Black) and inspired by both the graphic novels and the original film from director Bong Joon ho, the TNT drama Snowpiercer is set more than seven years after the world as we knew it became a frozen wasteland and those that were left stepped onto a perpetually moving train with 1,001 cars that circles the globe. Even though there is a very clear and strict class and social division between passengers, when a grisly murder threatens to ignite an already tenuous structure, the powerful head of hospitality, Melanie Cavill (Jennifer Connelly), turns to Andre Layton (Daveed Diggs), the world’s only surviving homicide detective, to keep the balance.

During this interview with Collider, co-stars Alison Wright (who plays Ruth Wardle, Melanie’s right hand in Hospitality) and Mickey Sumner (who plays Brakeman Bess Till) talked about how much they were told about the series during the audition phase, the roller coaster journey Snowpiercer took in finally getting to the screen, starting over with a different pilot script and brand new characters, and what these incredibly detailed sets are like to work on.

Collider: When this came your way, did having a movie and a graphic novel to refer to, help you in having a sense of what this could be?

MICKEY SUMNER: When the pilot came through, I don’t actually know if they said it was called Snowpiercer when I auditioned for it. It wasn’t. I didn’t actually know. They gave me the notes that, “It’s to play a cop, and there’s mystery.” I didn’t know it was set in the future. I didn’t know it was a train. That was it.

ALISON WRIGHT: I got the first six scripts and a full breakdown. Sorry about that.

SUMNER: I think I only found out that it was Snowpiercer on my callback. It was untitled when I auditioned for it. I had no idea what I was doing, but I somehow managed to convince them I was perfect for that role.

How do you even really audition, when you don’t have a clue what you’re auditioning for?

WRIGHT: Do not get me started.

SUMNER: It happens all the time. All of the auditions are top secret, untitled scripts, or a pretend script with a pretend name and fake sides. It literally doesn’t matter. They just want to see what your hair looks like on camera. I’m sorry, that’s a joke. But not really. But a little bit. But not really.

WRIGHT: There’s an element of truth in every joke.

Alison, did you really know that much more about it?

WRIGHT: I didn’t. I was joking.

SUMNER: She was winding me up.

WRIGHT: I can’t remember what I knew, to be honest. It was so long ago, that we did the original pilot. It was 2017, three years ago. We’ve been doing it, for a long time.

SUMNER: I auditioned for the show when my son was four months old, and he just turned three.

What was it like to go through a journey like that, with different pilots, different directors, and different networks, before finally getting on the air?

SUMNER: It’s a relief. I had this joke that the real world would freeze over before it ever aired. But no, I’m really excited that it’s [finally] out. The journey has been long and interesting, but the people on the journey has been like the greatest gift in my life. They’re really fun, beautiful people who I now call family. It’s been a great ride.

WRIGHT: It’s not always great just to rush things and get things out, when they’re not ready, as we’ve seen in the cinema. It’s good that they took the time.

When the pilot got re-shot with a different showrunner and director, were there big changes made?

WRIGHT: In terms of changing showrunners, it wasn’t that changes were made. It was a different script. It was a whole new script, and different everything.

SUMNER: It was a different show with different sets and different costumes. It was like a new job.

Did that change a lot with your characters?

WRIGHT: I got a brand new character. I’m not even the same person that I played in the original pilot. That was unusual. I love this character. She’s hilarious. She’s a lot of fun. I really enjoy playing her. I’m very happy playing her.

These characters all have secrets and there’s a lot of mystery on this show.

WRIGHT: Yeah, there are a lot of people to meet on the train. There are a lot of different characters and everyone has their own story with different circumstances. A television show is a great format for this story ‘cause there’s so much more to discover, in all of these different cars, which will give it plenty of longevity. There’s also something really interesting about getting to recreate yourself and reinvent yourself, when the whole world has ended. You’re in this new place, so who do you decide to tell people that you are? You’ve got a choice. You don’t have to be who you were.

SUMNER: There’s no Google.

Alison, is it fun to get to wear this uniform?

WRIGHT: Yeah, when you have a costume that you can’t sit down in, whatsoever, it tells a lot.

SUMNER: You never see Ruth sitting down.

WRIGHT: Because I can’t sit down. But the costume is great. It’s beautiful. I love it. This show is nice, visually, because there are so many different sorts of people, in many different uniforms. Everyone has to have a job and a purpose on the train, except the ultra-rich, whose job was to fund the train, in the first place. We all have our roles and Ruth likes to make sure that everyone is where they’re supposed to be, and that everything is nice and in order for Mr. Wilford, the way he likes it.

What sets Ruth off?

WRIGHT: People not doing what they’re supposed to do, raising above their station, thinking that they deserve something more than they’ve got, disobeying Mr. Wilford, disrespecting Mr. Wilford, being a tailie In her opinion, the tailies threaten the balance of the train. There are a few hundred extra bodies on there that weren’t supposed to be on there, and now we have to accommodate that. They’re slowing us down. They’re draining the life force of the train faster than it should have been. They didn’t have tickets. They shouldn’t be there. That’s what she thinks.

Will Andre Layton (Daveed Diggs) continue to be the thorn in everyone’s side?

SUMNER: No comment.

WRIGHT: I would say so. If somebody has deep-seeded hate towards another person, it’s not going to go away overnight.

What do your characters think of Melanie (Jennifer Connelly)?

SUMNER: For me, she’s hospitality. Our worlds don’t really collide.

WRIGHT: Everyone on the train thinks that she is exactly who and what she says she is.

Is it dangerous to even get suspicious of anyone else?

WRIGHT: We’re in a brand new society and a brand new world, and people want to do for themselves and provide for themselves. To a certain extent, that always puts people on edge, a little bit. You have to be aware of what’s going on and what the game is that’s being played. If you want to make something of yourself in this society, you ought to be clued into what’s going on, even if that means being suspicious. Ruth won’t like it, if she knows you’re doing it.

SUMNER: Up until the point of this show, for the seven years, the order has been working. It’s kept everyone alive. The masses are not really thinking about deep conspiracies, at this point. They’re literally like, “We’re alive, we can eat, and we’re warm."

WRIGHT: Seven years in, people get up and go to work, and they do their job. They’re not necessarily always thinking about the bigger picture of what’s going on outside of the train. This is a living, functioning society. People get up and go to work, and they’re cops, they’re cooks, they’re cleaners, or they’re hosts, and they’re just living, every day, like we are.

What are these sets like to work on? Do they feel claustrophobic and confined?

WRIGHT: Yeah. We’re not really faking that.

SUMNER: It’s great. You don’t have to pretend very much. They also move.

WRIGHT: There are people outside, wobbling them.

SUMNER: You always have this little tremor. No one is doing fake train acting. Well, sometimes we have to. There are a few sets that don’t wobble. I think the sets make life so much easier. There’s no trying to fill those imaginary holes. It’s just there, and you’re in it. Even just the way you walk down a corridor, if there are three people walking up the corridor, who gives way? All of those dynamics are really rich.

WRIGHT: And it was created with money. Unless you’re in the tail, the rest of it’s phenomenal.

SUMNER: Well, my barracks aren’t phenomenal. I have a bunk bed. But I remember going into like first-class for the first time, and being like, “What?!” My first two weeks were working in the tail, and then, suddenly, you go up to first-class and it’s so different that it’s infuriating, even in a pretend context.

WRIGHT: There are windows, chandeliers, martinis, and orchids.

Are there any cool details that we couldn’t even see, watching it?

SUMNER: There are so many. It’s so detail-rich.

WRIGHT: I don’t know. I would think they try their best to get all of that stuff on camera.

Was it an adjustment to deal with acting while you’re moving around in the train cars?

WRIGHT: If it’s a big jolt, you can react to it, and different people will react differently. Some people won’t move at all, while someone else might make a fuss about it.

SUMNER: Something to get used to was the sound of the train. It was a little bit noisy. Season 2 got less noisy, but in Season 1, it was noisier. I was like, “Should we stop for sound?” And they were like, “No, that’s the train.” Now, I don’t even think about those things.

Snowpiercer airs on Sunday nights on TNT.