SPOILER ALERT: This story contains details about upcoming Riverdale Season 2  storylines on The CW.

The CW’s Riverdale has long teased an upcoming musical Glee-esque episode, and today they previewed it to fans at PaleyFest. Set to air on April 18th, the episode has almost the entire cast singing and dancing as they put on a high school performance of Carrie.

“It was something we talked about even in Season 1 to do a musical episode,” showrunner Roberto Aguirre-Sacada said during a panel discussion after the screening. “We ran out of time, and we were doing the second season, and we planned the musical for halfway through, but we just kept pushing it and pushing it, so it was, ‘We’re either doing it now or not doing it.'”

“He had a love for it,” EP Greg Berlanti added, “and it really just fit so well with the characters and the storylines that they were doing.”

The cast also obviously relished the experience. “It was a fun and really rewarding thing to do after 17 episodes of Riverdale,” Madelaine Petsch, who plays Cheryl, said. “It was really fun for us, and we came together and got to work together for the first time in a while.”

Riverdale – based on the Archie comic stories – follows the lives of teens and their families in a fictional and fantasy-ridden small town.

One thing PaleyFest fans were waiting for was the return of the mysterious Black Hood, and Aguirre-Sacada hinted they might soon find out the true identity of the killer.

“For the last 10 episodes or so, we’ve had a pretty clear idea,” he said, “and have been writing towards that.”

The previewed episode provided some other great revelations for fans, including several reconciliations; a confrontation for Archie (KJ Apa), and Cheryl dealing with the fake blood from the Carrie musical set.

This last moment on set was, Petsch said, “sticky! There was a bar they had to put up for me to put my arms on between takes, because my arms would get stuck to my sides. The shower afterwards was sweet relief.”

Things have been tense lately between Cheryl and her mother since during the last-aired episode, she had Cheryl shipped her off to a nunnery for some gay conversion therapy after she began a romance with bisexual character Toni (Vanessa Morgan).

The storyline exploring Cheryl’s sexuality has, for Petsch, been a rewarding experience. “I don’t think it was a realization,” she said. “It’s something she’s known for a long time, that her mom’s pushed down.” Feedback from fans has been overwhelmingly positive. “I feel so welcomed by that community,” she said. “Unfortunately, it’s still happening, parents not accepting their children.”

For Aguirre-Sacada, that storyline was an obvious choice. “We had conversations about it early on,” he said. “It was something that we talked about when we introduced the character of Toni Topaz, a bisexual character from the comic books.” He added there was more to look forward to on that front. “The episode that you guys haven’t seen is really powerful. It airs this Wednesday, and it’s a powerful episode between Cheryl and Toni. We’ve been thinking about it for a while, so it’s nice to see it come to fruition.”

Another storyline fans are hoping for is a relationship between Alice (Mädchen Amick) and FP (Skeet Ulrich) and that may emerge in the next episode, Aguirre-Sacada said. “There’s a big episode for Alice, the serpents and FP, so if people are interested in seeing more of FP and Alice, I think you should watch this week’s episode.”

Riverdale airs Wednesdays on The CW at 8pm.