The CW’s superheroes will each have some potentially world-destroying problems to deal with when the four series — Arrow, The Flash, Supergirl, and DC’s Legends of Tomorrow — return over the next week.

On the sixth season of Arrow, not everyone will make it off Lian Yu alive. In season 4 of The Flash, Barry will have been gone from Central City for six months after appeasing the speedforce to save Iris’ live. On Supergirl season 3, Kara will have to come to terms with the major sacrifice she made to save Earth. And on the third season of Legends of Tomorrow, the team will be forced to fix the anachronisms and aberrations they caused when they visited a time to which they’d already traveled before.

Rotten Tomatoes spoke with the executive producers from each of the DC series about how their superheroes will save the day, which villains they’ll have to overcome this season, and new cast members, including genre favorites such as Smallville vet Erica Durance, Lost‘s Michael Emerson, Heroes star Adrian Pasdar and more.

Read on to find out what to expect during The CW’s premiere week, kicking off Monday, Oct. 9.

Supergirl

Premieres: Monday, Oct. 9 at 8 p.m.

Stars: Melissa Benoist, Chyler Leigh, David Harewood, Jeremy Jordan, Calista Flockhart, Mehcad Brooks, Katie McGrath, Chris Wood

Supergirl (Benoist) made a major sacrifice at the end of the season 2 finale, sending her love, Mon-El (Wood) away in order save Earth. While the plan worked, Earth might not be safe for long thanks to a mysterious Kryptonian pod containing a baby who will allegedly reign over Earth. Executive producer Robert Rovner reveals exactly how the baby will wreak havoc and teases Mon-El’s eventual reappearance.

Rotten Tomatoes: What can you say about the baby in the teaser from the end of season 2?

Robert Rover: The baby is Reign, played by Odette Annable. She will be a world killer who is genetically engineered by these people on Krypton. We’re excited to tell that story this season, to see Reign come up head-to-head against Supergirl.

(Photo by The CW)

When Mon-El comes back, is he going to be the same guy?

All I can tell you unfortunately is that Mon-El will return at some point, but when he returns and how is one of the central mysteries of our season.

When he does return, is there a possibility that he and Kara could still have a relationship?

She’s grappling with the events of the season finale as we start the season, and she’s wrestling with what it means to be human. How and when it impacts with the return of Mon-El, that we can’t really talk about.

(Photo by The CW)

In the Comic Con trailer, Kara says, “I am not a human. Kara was a mistake.” Is that just her in the aftermath of this sacrifice she had to make in the finale, or is that just growing pains now that she’s accepting her identity as Supergirl?

I think it’s growing pains. She learned the price of being vulnerable and the price of falling in love. She was put on Earth for a reason, so she’s grappling with [the question of] is it better to compartmentalize and throw herself into work at the expense of her relationships and be focused on saving the world — which in some respects is emotionally easier — or is she prepared to try and take a chance on fulfilling her human destiny as well?

What can you say about Adrian Pasdar’s new character?

He’s wonderful. He’s playing Morgan Edge. We’re really excited to have him on. He comes from the comics, and he’s a titan in business. He comes to National City with his own agenda that quickly comes into conflict with Supergirl’s.

(Photo by The CW)

And what about Erica Durance taking the place of Laura Benanti?

Oh she’s wonderful. We’re really excited to have her. It’s great. She’s one of the legacy actors. She was in Smallville as Lois Lane. We always love bringing people who have been part of the DC Universe back into the fold in different roles, so it’s been kind of great having her back in the DC family. We were sad that Laura Benanti couldn’t continue, and we loved her in the role of Alora, but it’s great to have Erica stepping into the role. Kara’s roots and her parents and that loss are so central to her character, so we thought it was important that we continue to have that presence in her life on Earth.

The legacy casting has been so fun. Are there any other people you want to try to get on at some point?

We love having them on and so whenever a new character comes up, we think about if there’s somebody that’s been involved in the DC Universe that could play that part. But besides Erica and the ones we have, like Helen Slater, who continue on the show, we don’t really have any other plans at the present. We love it, and we think the fans love it. We love seeing people that we know and are familiar with step into other roles. And what’s great about them is that they’re all wonderful actors as well. So, you get the excitement of seeing them in the new role but they also bring a lot when they take on these new characters.

(Photo by The CW)

Alex and Maggie’s engagement seemed a little quick. Are they going slow it down a little when we get back?

We love Sanvers and we loved watching them fall in love last season. And we’re disappointed that Floriana [Lima] had other opportunities and other things she had to pursue this season so that she couldn’t come back full time, but what we are able to do is tell a story for them that really honors their relationship. That’s what we’re pursuing and we hope the fans will be as moved by it as we are.

On a larger scale, when Supergirl premiered, seeing Melissa interact with little girls dressed as Supergirl was so inspiring. Then there was Wonder Woman‘s success over the summer. Do you feel a cultural importance on a larger scale when you’re writing, or are you focused on the smaller scale of just making a good show?

One of the things I think we were able to do this season was to tell stories that really spoke to issues that were going on in the real world, and to see how this very strong woman could navigate that and allow us to discuss issues that were topical, and to tell stories about inclusion, and acceptance, and about LGBTQ rights, and all of the stuff we’ve been able to tell. We do focus on letting Supergirl be a voice of strength and optimism and hope, to tell stories that are reflective of what’s going on and to be a source of strength and be there for people who are dealing with all of the stuff that we’re dealing with. I think too it shows that it’s not always her super powers that save the day. It’s her voice and all of her strength that can inspire people that they don’t have to be a superhero to make a difference, that they can use their own strength to persevere. Hopefully the stories that we’re telling challenge people, and help embolden them to be the best that they can be, to persevere under the most trying of circumstances.