Supergirl’s” second season ended with Mon-El (Chris Wood) being rocketed to space after a device is triggered that forces all Daxamites to leave Earth.

When the third season picks back up six months later, Supergirl (Melissa Benoist) is still struggling with that loss. In her grief, she’s begun pushing people away and focusing her time entirely on her super heroic duties.

Variety spoke with executive producer Andrew Kreisberg ahead of the Season 3 premiere about Kara’s core struggle this season, what to expect from Reign (Odette Annable) and planning this year’s four-part DC crossover event.

How is Kara dealing with the loss of Mon-El?

She’s definitely turned inward. The theme of the season is really “Is it better to be alien, or better to be human?” and when we pick up with her six months after the Season 2 finale she’s decided it’s better to be an alien. She’s systematically pushing people away and embracing being Supergirl. The irony is Supergirl has never been more powerful – or more of a hero – but Kara has never been less of a good sister/friend/employee.

Does the question of if it’s better to be alien or human or what it means to be human, something that she’s been struggle with for years – really kick up after Mon-El was forced to leave?

Yeah, one of the things we explore this season is that she has always been dealing with this. She’s always been dealing with loss. The thing that makes her more interesting to me than her cousin Superman is that she remembers Krypton. She was 13 years-old when she saw her mother and father die and her friends die and her planet explode. You start to wonder how much loss this woman can take before she begins to wonder if the problem is she’s caring about people too much. We have an episode this season of a flashback to the girls in high school, and it shows that this is something she’s been dealing with her whole life.

Reign (Odette Annable) is the big bad this season, and in the grand scheme of DC history she’s a fairly recent addition. What was it about the character that made her the fit for this season?

We wanted someone who felt like a mirror image of Kara – sort of the dark mirror – and we thought it would be interesting to see someone go on the same heroes’ journey that Superman and Supergirl went on, but turn out to be the villain. It’s not quite the Reign you’ve seen in the comic books. There has definitely been a bit of our own imagination added to it.

Katie McGrath – who plays Lena Luthor was bumped to series regular for the season. What’s in store for her when it comes to her relationship with Kara and her working to change the stigma of her family name?

A lot of this year is going to focus on Kara and Lena’s friendship and how it is changing. They find themselves in a new partnership position that neither of them were really expecting – which both causes problems and allows them to become closer. Lena, to me, is like a time-bomb waiting to go off because of her last name and not necessarily anything that she’s done. You’re always sort of wondering when’s the one thing that happens to her – when does she get pushed so hard that she reacts like her brother?

Last season James (Mehcad Brooks) put a lot of focus on becoming Guardian even though he was running CatCo. Will we see him more as the head of CatCo this season?

Yes. The one thing we really wanted to get back to, that we sort of lost last year, was the “Super Friends” – the OG team of Winn [Jeremy Jordan], James and Kara investigating things. There is a bunch more opportunities for that this season.

When it came to beginning to plan for this year’s crossover, what were you thinking when you realized you had to juggle a true four-show story, along with pulling off Barry (Grant Gustin) and Iris’ (Candice Patton) wedding, while also topping the alien invasion from last season?

If we ever had correctly guessed how hard these crossovers would be we never would have done them. The biggest problem with the crossovers are we learn so much doing them, but then the next time around we make it bigger – so whatever we learned is helpful but there are now all these other things that we weren’t anticipating. This year is the first year it’s a true four-part story, and it really does hold together as a four hour mini-series, and for that we’re really proud and excited. I’m more concerned about what the hell we’re going to do next year, but I remember thinking last year “what the hell are we going to do next year?” and somehow we came up with something that we’re really excited about.

“Supergirl” season 3 premieres Oct. 9 at 8 p.m. on the CW.