After three seasons, The Flash is changing things up.

During The CW's Saturday DC Comics TV panel at PaleyFest, executive producer Andrew Kreisberg revealed a big change for season four of the Grant Gustin starrer.

"Next season, we're not going to have a speedster as the main bad guy," Kreisberg said as the packed Dolby Theatre erupted in thunderous applause and cheers.

For show's entire run thus far, every season has been focused around a speedster as a villain, beginning with Reverse-Flash (Tom Cavanagh/Matt Letscher) in season one, continuing with Zoom (Teddy Sears) in season two and mysterious god of speed Savitar (Andre Tricoteux) in season three. Viewers clearly seem ready for a new chapter in the Flash mythology when it comes to the season-long villain arc, but Kreisberg claimed that Savitar was the right villain for the current story.

"With Savitar, we know who he is, and we've been planning this for a while," said Kreisberg. "The first two seasons were about having fun with his powers, and this season for Barry [Gustin] is really about the pitfalls of having powers, and that's the story we wanted to tell. That's why Savitar was the perfect villain for that story."

But before the Flash producers can look ahead to the already-announced fourth season, they first have to focus on the upcoming musical crossover with Supergirl, which begins Monday on Supergirl and wraps Tuesday with The Flash.

"It's like a gimmick episode," said Kreisberg. "The person who did those episodes the best was Joss Whedon [with Buffy the Vampire Slayer]. You think of 'Hush' or 'The Body' or 'Once More, With Feeling.' The best thing about those episodes were that they didn't stop the ongoing narrative of the season. Those episodes really spoke to what the characters were going through."

"We set it up so that, on Supergirl and The Flash, both Barry and Kara [Melissa Benoist] would be at a romantic crossroads," he added. "They're at the same place, essentially, so they can go on this journey together to get back the love they think they lost or not."

Arrow star Stephen Amell then joked about all the romance storylines across all four CW DC Comics shows: "You guys love torturing the viewers. Admit it!"

After the vocal audience responded with cheers, Amell reflected on his sense of accomplishment after completing Arrow's 100th episode during the big four-show crossover earlier this year. "I feel like the path to [episode] 200 will be easier," he said.

This season, The CW added CBS import Supergirl to its roster of DC fare, which also includes The Flash, Arrow and Legends of Tomorrow. Among a few changes that came with jumping networks was a shift from production in L.A. to Vancouver, British Columbia, as well as an expansion of the alien storyline and its connections to the real world. Supergirl producers were quick to point out that the latter reveal had nothing to do with the network change.

"No disrespect to CBS — who were very gracious hosts to us," said Kreisberg. "And, truth be told, we pitched a lot of what we were going to do in season two to CBS, and they were very cool with the change. It was more just in terms of us, and what makes Supergirl special and why is it different from the other shows? One thing that Supergirl can really do because it's baked into the DNA of what it means to be a woman in the world and finding her power, when we were crafting this season, we talked about what was going on in the world with immigration, journalism and LGBT rights. We realized this show and this cast could handle mixing that real-world stuff into the superhero world."

He continued, "I'm as proud of the episodes where we touched on that more than anything I've done in my career."

Supergirl airs Mondays at 8 p.m., The Flash airs Tuesdays at 8 p.m., Legends of Tomorrow airs Tuesdays at 9 p.m., and Arrow airs Wednesdays at 8 p.m. on The CW.