Arrow Executive Producer Andrew Kreisberg talks about the evolution of Summer Glau's character, Isabel Rochev.

Warning: SPOILERS for tonight’s Arrow, titled “The Man Under The Hood,” as well as the next step for Isabel Rochev will be discussed within.

One of the first big “gets” that was announced for Arrow Season 2 was the casting of genre fan favorite Summer Glau (Firefly, Terminator: The Sarah Connor Chronicles) as Isabel Rochev, a character we learned a whole lot more about with tonight’s show. However, earlier this week at a press Q&A, Arrow Executive Producer Andrew Kreisberg admitted to us that the plan for Isabel was not always fully planned out or set in stone.

“Isabel was the one thing that we were’t entirely sure about as we were developing the season,” Kreisberg admitted to reporters on Monday morning. “Truthfully, there was a very early iteration of this [season] where Sara started the season as Ravager, and then we switched over. We always had that paradigm of Slade having [that role] in the back of his mind. Obviously, we didn’t want to make her Rose and have that trajectory. Part of the reason Isabel disappeared for a while was because we still weren’t quite sure which way to go – whether she should be an ally or a villain. We had written it so that it could turn out either way; just, as we were coming down, the scene that I was picturing was Isabel, Slade and Sebastian in Oliver’s office – like the triumvirate of evil – and once that happened, there was no way she was not going to be Ravager.”

“It is funny, because when Summer took the part, I was up there on set with her, and she’s like ‘I’ve never done anything like this. I feel much better if I’m kicking somebody!’ And I’m just like ‘You’re so good; you should give yourself more credit! We wanted you because you are a good actress and you feel amazing in this part, not because you can kick ass.’ And then I got to call her and say ‘Hey. We changed our minds. You get to kick ass.’ In 18, when she does [kick ass], it’s like ‘oh yeah’,” Kreisberg enthused.

“One of the things we’re most proud of with the show is the casting – obviously the regulars are amazing, but I feel like our guest cast, between Caity Lotz, and Katrina Law, and Kevin Alejandro, and Summer… the show is constantly populated with these great people who are also bringing with them their baggage. I don’t mean that in a bad way, I mean it in a good way,” Andrew continued. “As soon as you see Katrina Law, you’re like ‘Oh yeah! I should be afraid of her, because she’s from Spartacus’!” As such, Andrew knew right away that the audience would take to Summer kicking ass, considering her previous on-screen experience doing that on several other shows. “It worked out really well, and now that she’s got the evil juice in her, as we call it in the writers’ room, it’s amazing,” he said.

What’s next for Summer Glau and Isabel? Stay tuned…