When The Flash returns for Season 3 on The CW on October 4th, everything will be different, as Flashpoint takes effect. After defeating Zoom, Barry Allen (Grant Gustin) made a decision to speed back in time to the night his mother died to stop Reverse Flash from killing her, changing everything in his world. And while that decision brought him the life he’s always dreamed of with his parents, the ripple effect that he’s created seems to have, irrevocably changed his past and redetermined his future.

At The CW portion of the TCA Summer Press Tour, executive producer/writer Aaron Helbing sat down with Collider for this exclusive interview about where things are headed for Season 3, the plan for a lighter tone, the consequences of the Flashpoint universe, this season’s big bads, the WestAllen relationship, and Kid Flash. Be aware that there are some spoilers.

Collider: After how dark things got in Season 2, what can you say about the story you’re telling in Season 3 and where things are headed?

AARON HELBING: Well, Zoom was a really, really dark character. When we introduced his backstory in Episode 218, you instantly understood why he was the way he was, having his mom murdered in front of him. It’s interesting because we got to explore what could have happened to Barry, had Joe not been there, had Iris not been there, and had love not been there. So, yeah, we went to a dark place. This season, we definitely plan on having a lighter tone. Evil is still out there, so you still have to respect that. I don’t think it will be as dark as Zoom. When we meet Barry, he’s living with his parents. I feel like this has been a moment that Barry has been wanting since his mother was taken from him. Who wouldn’t want that? And then, Zoom took his dad last season. So, when you meet him, you see this happiness. He finally is having the life that he’s always wanted, but there’s always a give and take to everything. While he has his parents, he doesn’t have Joe in his life. He didn’t grow up with Joe as a foster father. He didn’t grow up with Iris right there, getting to see her every day. He knew her from grade school, but they didn’t have the same relationship. Those are big differences. He didn’t go to S.T.A.R. Labs and have Cisco and Caitlin and Dr. Wells. These are adjustments that he has to get used to. But, being with his parents overshadows everything.

Will it affect Barry Allen mentally when he realizes just what he’s done?

HELBING: As we explore the Flashpoint universe, he’ll realize that there are consequences to the choices that he made, and he has to deal with those consequences. Every time you make a choice, it can go A or B. And when you make that big of a choice to go back in time, 15 or 16 years, and stop Reverse Flash from killing your mom, there are going to be gigantic ramifications because of that. So, I think Barry is aware of that.

Reverse Flash is going to be taunting Barry for the choices that he’s made. Was it fun to have him come back and make Barry face what he did?

HELBING: Yeah. And when you have someone the caliber of actor that Matt Letscher is, and he’s such a nemesis, he loves it. He hates The Flash. When you look at the history of Reverse Flash in the comic books, he was obsessed with The Flash and wanted to become The Flash, but he couldn’t. He became so obsessed with The Flash that he had to become better than him, or that’s what he thinks. His entire mission in life is making Barry Allen’s life a living hell, even just where Reverse Flash is, being able to taunt Barry as much as he can. He’s just going to say whatever. It’s like, “You’ve got me, but I still hate you and I’m going to do everything I can to make you miserable and to make you believe that the action that you took was catastrophic.”

What can you say about the big bads you have this season and what Barry is facing?

HELBING: I’m really excited about Doctor Alchemy because we haven’t had someone who’s an alchemist. He can take X and turn it into Y. That mirrors what happened with Barry when Barry was just this normal CSI who was happy go lucky, and then he got struck by lightening with the dark matter from the Particle Accelerator. That was almost a form of alchemy, where it changed him into The Flash. We can really explore alchemy, in that manner of being able to take X and turn it into Y, and see how that mirrors what actually happened to The Flash and all of the meta-humans in Central City. We’re going to have a speedster, as well. Savitar is an evil speedster.

Where are things at between Barry and Iris?

HELBING: In the Flashpoint universe, he hasn’t really grown up with her. They’re essentially strangers. She’s someone he used to know, and he’s someone she used to know, back in the day in grade school. It’s exciting because it’s like, “Oh, this is what would have happened, had Reverse Flash not done this and had Barry not become The Flash. He would have been a normal guy, nervous about going up to a pretty girl that he’s had a crush on forever, and get to know her and try to have a relationship with her.” For us, that’s really exciting because we get to explore that.

Is there anything you would say to reassure the WestAllen fans who are nervous about the Flashpoint storyline?

HELBING: Barry Allen and Iris West are an iconic relationship. We set it up, at the end of Season 2, that they were going to get together, and then he undid it. But, these two are destined to be together. I would say to keep watching. As with destiny, things end up playing out the way you hoped they would.

What can you say about Kid Flash and how he’ll be different from other speedsters?

HELBING: The thing about Wally West, and the way we set him up in Season 2, is that he has this need for speed with the drag racing. That’s in his DNA. Even when he stopped drag racing, he’s an engineer who’s trying to design and develop turbo-powered, fast cars. Those aspects are always going to be in his DNA, and he’s always going to want to go as fast as he can. So, when you meet him in Flashpoint, he is The Flash. He’s Kid Flash, but he’s The Flash. He’s a speedster who just wants to do the right thing, but he also is gonna do it his way.

How challenging is it to explore so many different speedsters, and make sure that they’re all different with their own personalities?

HELBING: To me, it’s no different than when you create a new character. They’re still real people at the core, so we dive in and explore who the person is, deep down. The way we explored Zoom was that we dove into who he is and what causes someone to become evil like that and how we can play that. So, with Zoom, we mirrored what happened to Barry’s parents and what happened to Hunter’s parents. That’s really at the heart. We always want to get underneath the character and look at them as real people. They don’t know they’re on a television show. (Executive Producer) Andrew [Kreisberg] says that, all the time. These characters don’t think they’re on The Flash TV series. These are living, breathing characters. So, we have to make sure that we do them justice and bring them to life, the best way that we can.

What is the dynamic between Cisco and Caitlin like now?

HELBING: Cisco is a bit different. The thing about Flashpoint is that, because of these actions, the reality of the world is different. There are different circumstances that create different relationships, and they just weren’t there. I love their dynamic. I love the way Caitlin and Cisco are a pair, and I don’t feel like we’ll lose that feeling.

The Flash returns for Season 3 on The CW on October 4th.