Fans who were excited to finally see DC Comics’ Nuclear Man brought to life onscreen last season on The Flash were likely shocked when the show’s second season kicked off with the death of Ronnie Raymond. While Dr. Martin Stein, Firestorm’s more cerebral half survived, there’s no nuclear hero without Ronnie…is there?

Tonight’s amazing episode of The Flash, appropriately titled “The Fury of Firestorm,” serves as the next chapter in the Firestorm saga. Not only does it find our heroes squaring off against Firestorm villain Tokamak, but it introduces Dr. Stein’s new partner in the Firestorm Matrix, an original character named Jefferson “Jax” Jackson. However, any comic book purists out there should know this before leaping to judgment—while Jax may be new, he shares quite a few qualities with Ronnie Raymond’s comic book iteration.

“What worked so well in the comic books was the idea that they were so different, Stein and Ronnie,” explains Executive Producer Andrew Kreisberg. “In the comic books, Ronnie is a jock. The character we created for our Ronnie was an engineer and was more mature and had a girlfriend. He was more of an adult.”

Jax is considerably younger than Ronnie. When we first meet him, it’s on a football field, and while he’s no longer a quarterback when he meets the S.T.A.R. Labs team, he still has that sensibility.

Of course, one character who will definitely have an opinion about Jax and his ultimate role is Caitlin Snow. After all, the man that Jax is replacing was her husband.

“I think is amazing in this episode,” shares Kreisberg. “Even though we did have the episode where Ronnie died and moved past it, this is really the episode where Caitlin deals with it. Because it’s The Flash and it’s about science fiction, she can grieve through wanting to protect her dead husband’s co-super hero. This episode makes me cry, especially at the end.”

Panabaker sheds some light on the cause of those tears.

“I think that what’s especially hard for Caitlin and maybe ultimately cathartic about this experience is that she’s so connected to Stein,” she explains. “Caitlin cares so deeply about him and for him because he is this sort of last connection to Ronnie. So she’s particularly invested in taking care of him and getting it right, and making sure his next partner is just as good, if not better than Ronnie was.”

That means Dr. Snow fans can look forward to a Caitlin who’s much more proactive this episode, and perhaps going forward throughout the season.

“This was Wells’ S.T.A.R. Labs. He created it and he was the boss, so we all followed along,” Panabaker says about Season One. “This year, it’s feeling a little bit different. We’re trying to figure it out, and whoever has the most expertise, passion or chutzpah about something tends to be the one we follow.”

“I think that Caitlin has taken the reins in a lot of ways, especially because they tend to sit around and argue about the best thing to do ,” adds Kreisberg.

“This grief for Caitlin is very different than last year,” Panabaker continues. “She was in a much darker, much unhappier place. I think there’s a new purpose for her being at S.T.A.R. Labs and especially with the loss of Harrison Wells as he was in Season 1, she’s going to find her new position and have different things to focus on. I think that helps her get over her devastation from losing Ronnie again.”

Ronnie may be gone, but Jax has an exciting future ahead of him. After his debut in tonight’s episode, the character—along with Victor Garber’s Martin Stein—will move on to DC’s Legends of Tomorrow, the third live action show to be set within the Arrow and Flash universe, where Firestorm will play a key role.

“Here you start to see the camaraderie, and when you see Legends you’re going to see a lot more while they’re merged,” says Kreisberg. “There’s more room for comedy than we’ve previously had before.”

But banter between Jax and his much older partner is only one thing the character brings to this swiftly growing TV universe. Jax, who’s portrayed by Attack the Block’s Franz Drameh, is African-American, providing some always welcome diversity to The CW’s slate of super heroes.

“He’s so good!” Kreisberg enthuses (with Panabaker’s excited agreement). “Honestly, we’re always so proud to have another African-American super hero with super powers. For a whole generation of kids, this show is their entry into the super hero world. For them,Firestorm will always be African-American and we’re so proud of that.”

Consider us fired up!

“The Fury of Firestorm” debuts tonight. The Flash airs Tuesdays at 8 p.m. (7 p.m. CST) on The CW.