Season 3 of The Flash was a bit of a downer, to say the least, but that's what happens when your super-powered future self turns evil and time travels into the past to kill your fiancee. Luckily, Season 4 sounds like it will bring back some of the lighthearted whimsy that launched the show in the first place.

When speaking with TV Guide, executive producer Todd Helbing promised more jokes and a speed-less villain for Season 4. Plus, he shared some dish on Barry (Grant Gustin) and Iris' (Candice Patton) journey to the altar in the four-way crossover with Arrow, Supergirl and Legends of Tomorrow!

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When Barry returns, how long has he been gone and how has his time in the Speed Force affected him mentally and emotionally?
Todd Helbing: When we start the first episode, he's been gone for six months. When he comes out, he's not quite the same Barry that you saw go in. It sort of allowed him to deal with all of the baggage that he's been carrying around for the first three seasons. You get to see the sort of Season 1, fun-loving, 'I love being a speedster' Barry Allen, which is nice and fun to get back to.

You've said Season 4 won't be as dark as Season 3, so how did you guys go about lightening up the show?
Helbing: The first episode is probably the closest tonally to the past three seasons, and even that shifts a little bit. It really kicks off in Episode 2. Everything starts with Barry as far as his tone... When he sort of comes out and has let everything go, it certainly has a trickle down effect with the team. There's a lot of jokes, there's a lot of fun scenarios. We're really swinging for the fences as far as the fun factor is concerned.

How will the team react to Barry's return after saving Central City without him for 6 months?
Helbing: When he comes out, he just wants to be The Flash again, so he's happy to go take down the villains or go save the day by himself. He's very eager to do that. But Wally (Keiynan Lonsdale) is still part of the team, and Iris is in charge, and Vibe (Carlos Valdes) has been going out. They've been working as this unit without him for six months. So when somebody's gone and they come and they step into the leadership role, there's some bumps along the way and that's what happens. It's not a smooth transition, really, for anybody. So Barry starts to realize his decisions and how they're starting to affect the team. A lot of that plays out with his relationship with Iris.

Grant Gustin and Candice Patton, <em>The Flash</em>Grant Gustin and Candice Patton, The Flash


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Speaking of that relationship, we know we're getting a wedding in the crossover episode. What can you say about how Barry and Iris get to that point?
Helbing: Obviously they were engaged at the end of the season and they sent out the save the date cards, but there's a big gap in what has happened from that point when he left. So they really have to work on getting back to the place where they left off, and that's not something that happens overnight. It's going to take a few episodes to lead up to the point where they're both ready to say, "I do."

How does Killer Frost (Danielle Panabaker), who's also still Caitlin, factor into this season?
Helbing: Caitlin had to try to figure out who she was exactly. Was she Killer Frost? Was she Caitlin Snow? She kind of went on her own journey — kind of like Barry went on his when he went into the Speed Force — figuring out how to deal with this power that she has and that she doesn't really want to have. So when she comes back, she's definitely not the goody-two-shoes Caitlin that you've known and loved for three years. She's got a little bit more edge to her, I would say. And slowly you start to realize why exactly she's changed a little bit.

She's had such bad luck with romance the past three seasons. Is that anywhere on the horizon for her in Season 4 or is she taking time for herself?
Helbing: She's going to take some time for herself this year. I think dealing with the Killer Frost and the Caitlin Snow of it all, that's more than enough for her. She doesn't need a relationship on top of it.

Carlos Valdes and Jessica Camacho, <em>The Flash</em>Carlos Valdes and Jessica Camacho, The Flash


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We're also going to see Gypsy (Jessica Camacho) again, so what brings her back around? What's her relationship with Cisco looking like?
Helbing: Those two have steadily been dating for that six months and their relationship is blossoming, you could say. Like any relationship, it has its ups and downs and Cisco, in an early episode, kind of does something that rubs Gypsy the wrong way, which is kind of fun. And in an episode in the near future, you get to meet Gypsy's father, Breacher. That whole storyline is one of my favorites so far this season. It's hilarious.

What can you tease about The Thinker and how he'll be different from previous villains?
Helbing: Well, he's obviously not a speedster, so his methodology is completely different. He's really more of the long game villain, who is playing chess. What you see is exactly the pieces that he's playing with and where he puts them, and he's controlling the moves. He's sort of created the problem for Barry and simultaneously solving the problems he needs solved when he needs them. So it's a lot of fun, and it's probably the most psychological-based villain we've had so far on the show.

Poor H.R. (Tom Cavanaugh) is no more, so does this mean we get Harry back full time?
Helbing: Harry comes back, and there's a reason why he shows up. [There's a reason] why he's come back and why he'll be sticking around. He's a little gruff, so there's a lot of growth for him personality-wise, but it's Tom Cavanaugh, and seeing him play as many different versions of Wells is what we love. So there's a nice array of different Wellses you get to meet this year.

And what can you tease about the Felicity (Emily Bett Rickards) crossover in Episode 5?
Helbing: She comes for a bachelorette party, and Iris and Felicity and Caitlin and Cecile have a night out on the town that does not go as most bachelorette parties go. They sort of get themselves in some interesting situations that they need to fight their way out of.

The Flash premieres Tuesday, Oct. 10 at 8/7c on The CW.

(Full disclosure: TV Guide is owned by CBS, of the CW's parent companies.)