“The Flash” “Supergirl” Crossover Spoilers: Darren Criss Cast As Villain For Musical Episode; Will Barry Allen and Kara Zor-El Do An Actual “Duet”?

Singing superheroes and villains? You better believe it.

The showrunners behind the special crossover episode of “The Flash” and “Supergirl” has tapped “Glee” alum Darren Criss to play the meaty role of Music Meister. TV Line first reported the news about the casting, which will have Criss reuniting with his former “Glee” cohorts Grant Gustin and Melissa Benoist.

Executive producer Alex Kreisberg said, “With our Flash and our Supergirl being Glee alums, how could we not have them go up against another “Glee” favorite like Darren Criss? We have been blown away by his talent over the years and we can’t wait to see what he brings to the Music Meister.”

There is not a lot much revealed for the upcoming episode, which will begin on March 20 on the CW. Kreisberg did share the team is quite excited about doing a musical episode, IGN reported.

“When we get to the musical episode, both Barry and Kara will find themselves at pivotal crossroads on their respective series, and the experience of going through the musical will have a great impact on both series going forward. To be able to do a musical episode is so exciting to us. If anything, it's what I would always love about what Joss Whedon would do [on Buffy the Vampire Slayer] with “Hush” or “The Body.” He'd have these very special episodes, but they were intrinsic to the ongoing storytelling that was going on." Kreisberg added.

The episode will be directed by Dermott Downs. Apart from Criss, Gustin, and Benoist, the episode will also showcase musical performances from Jesse L. Martin, Victor Garber (“Legends of Tomorrow”), Carlos Valdes, Jeremy Jordan, and “Arrow” alum John Barrowman, Entertainment Weekly said.