Snowpiercer's Daveed Diggs And Mickey Sumner Dish On Working With Sean Bean And Jennifer Connelly - Exclusive Interview

At the end of Season 2 of "Snowpiercer," de facto train leader Melanie Cavill (Jennifer Connelly) disappeared while venturing outside in the freezing cold, leaving Andre Layton (Daveed Diggs) and his cohorts behind on a train that soon splits in half. Season 3, which premieres tonight on TNT, picks up with Layton and his inner circle commanding a small ten-car "pirate train" in search of Melanie and a possible warm location to restart civilization.

Also starring Sean Bean ("Game of Thrones," the "Lord of the Rings" trilogy) and Mickey Sumner ("Frances Ha," "CBGB"), the "Snowpiercer" series is based on the 2013 cult-hit film of the same name by Oscar winner Bong Joon-Ho that follows a nonstop train circling the globe while carrying the last remnants of society who have survived a modern ice age. As leaders of the train rebellion, Layton and his ally Bess Till (Sumner) are embroiled in nonstop action that often leads them to solving mysteries together.

Diggs and Sumner, the daughter of legendary musician Sting, recently sat down with Looper to discuss the new season, including what it's been like working with Connelly and Bean, and what their dream spin-off show would be.

In the previous two seasons, Jennifer Connelly was a major presence on the show. But this season, she's presumably gone. How do you feel her exit has affected the show? And do you miss working with her?

Daveed Diggs: We're lost without her. We should give up. There's no way to move forward without Jen. [Laughs.] Well, for me from a story perspective, in a lot of ways that was Layton's biggest ally. They were enemies, obviously, but in terms of people who he could really work with to affect change, Melanie was his ally, and she's gone now, and now [Layton] has to figure out how to be a leader without that. That's a big wrinkle, but also, working with Jen is great when she's around. It's boss.

Mickey, I feel like every season Bess becomes a bigger, more important character. What's been the biggest challenge of portraying her? And, on the flip side, what makes her fun to play?

Mickey Sumner: There are no real challenges. The challenges are all fun. I embrace all of them. I love the physicality of this character. I love her awkward, vulnerable moments when she struggles to trust and struggles with connection.  I love her loyalty towards Layton, but, especially in Season 3, she really starts to question and prod at his mission, which was really fun ... to not always agree with Andre. Yeah, no challenges, just all fun.

Sticking with you for a second, Mickey, your dad has done some acting, including a great comedic role in the recent "Only Murders in the Building." Do you guys ever trade acting notes, or did he give you any memorable advice going into the series?

Sumner: No ... I don't consider my dad an actor. I think he comes to me for advice. I'm just kidding. He's a great performer, but we don't really talk about work stuff.

What are your favorite scenes to film together, and does any one scene in particular stand out?

Sumner: I have a couple.

Diggs: I love every scene with Mickey. She's my favorite.

Sumner: One day, they're going to write a show for Daveed and me, where we just get to play cops or detectives and get to be in every scene together because it's just too much fun. We had one really fun explosion scene...

Diggs: Yeah, we got a lot of good stuff this season, and in all seasons, but I'll put that out there right now, in case anybody's [reading] this — cop duo, cop comedic drama with me and Mickey ... I'm in, fully 100% in. So, somebody write it, and we'll do it.

Any interesting memories or scenes with Sean Bean? He makes a fantastic bad guy as Mr. Wilford...

Diggs: Sean Bean's at 11 all the time. My favorite scene I've ever shot with him is, I can't tell you about it because it's in this season, but he had such a lack of concern for his own safety shooting it, and I was terrified for him. He was just like, "Hit me!" He went for it, and I was very impressed, and had to reconsider my own physicality quite a bit.

Sumner: For me, growing up in England, Sean Bean was such a hero of mine. Any time to be on set with him has been a bit of a pinch-me moment.

In general, what has been the best memory, whether funny or poignant, that stands out the most from all three seasons so far?

Sumner: I think it's the cast and the crew. I'll say it and keep saying it, but it's one of the greatest jobs, in that I just fell in love with everyone, and we became a real family. These relationships we have created, off camera as well as on, are life-long, and I'm really grateful for it.

Diggs: Yeah, same. Particularly last season, which should have been really, really hard because the borders were shut. Most of us who used to go see our families at some point couldn't do that, but I got to spend so much time outside of the show with these wonderful people and become even more of a family. As hard as last season was, it was a testament to how wonderful the people around us are. We had a really good time.

Season 3 of "Snowpiercer" premieres tonight on TNT, with subsequent episodes airing every Monday at 9 p.m. ET.