The Flash will return next week with "All-Star Team Up", airing Tuesday, April 13, and The CW Network has released a brand new trailer, which reveals that Arrow stars Emily Bett Rickards (Felicity Smoak) and Brandon Routh (Ray Palmer/Atom) are returning to Central City. They've come to visit S.T.A.R. Labs as Ray needs help with his suit. Their timing turns out to be fortuitous because it's all hands on deck after a meta human named Brie Larvin (guest star Emily Kinney) unleashes hundreds of robotic bees to attack and kill her former co-workers, including Dr. Tina McGee (guest star Amanda Pays). A group dinner with Barry (Grant Gustin), Felicity, Ray, Iris (Candice Patton) and Eddie (Rick Cosnett) turns into a disaster.

The show's cast and crew also make an appearance at WonderCon in Anaheim, California yesterday, where executive producer Andrew Kreisberg revealed why Ray Palmer pays a visit to Central City.

"In episode 18, Ray Palmer is having some trouble with his Atom suit, and who better to go to for help than Cisco Ramon?"

Andrew Kreisberg also revealed that another Arrow star, Katie Cassidy, will be visiting Cisco in an upcoming episode. Here's what he had to say below.

"That's one of the most fun stories that we wrote, Cisco's interactions with Laurel. Cisco is us. What would your reaction be if you got to meet the Black Canary?"

In the comic books, Danielle Panabaker's character Caitlin Snow eventually becomes Killer Frost, a character fans may see sooner than expected.

"You're going to see her sooner than you think."

Andrew Kreisberg also teased a few villains that will be introduced in Season 2, debuting this fall on The CW, including one mystery villain fans will 'lose their minds over.'

"I think we definitely want to meet the Mirror Master next year. I'm sure Dr. Alchemy will show up at some point. And we've got one thing that hopefully people will lose their minds over."

The producer also teased the possibility of Wally West or Black Flash from the comic books making an appearance in the series.

"If there's something that existed in the Flash universe, no matter how crazy or how silly, there's a good chance it'll be on the show."

Andrew Kreisberg is also producing the Arrow / Flash Spinoff, which he described as "gonzo," with both shows working to set up the spinoff next season.

"It's going to be like the crossovers every week. It's going to be gonzo." (It's) insanity and off the rails."

Take a look at the trailer for The Flash's "All-Star Team Up", airing Tuesday, April 14 at 8 PM ET on The CW. What do you think about all these new details? Let us know what you think below, and chime in with your thoughts.