Fans are excited to see Supergirl and The Flash in a "Duet" Episode in the fastest superhero series. Viewers will witness the musical performances from Grant Gustin and Melissa Benoist, who are both former Glee casts and Carlos Valdes with John Barrowman set in the 1940's alternate reality.

"The Flash" and "Supergirl" episode on Tuesday, Valdes, and Barrowman who plays their respective characters as Cisco Ramon and Malcolm Merlyn. Both talked and shared what to expect in the most anticipated episode of "Supergirl" and "The Flash." For the over years, producers in the Arrowverse has been successful in pulling out a crossover.

Now, another epic crossover has planned by writers and producers of the Arrowverse using true and tried genre, the musical episode. Music Meister shows up, Kara and Barry Allen will be under his spell, team Flash and Supergirl's friends will be saving the day.

According to John Barrowman, the interesting part is the viewers have in the different world, some might call it musical world, Musical Meister world, or an alternate universe. He claimed that they are all in the minds of two truths of The Flash and Supergirl and the rest of the cast are what is in their head, Screen Rant has reported.

Barrowman explained that this is the reason why The Flash new him as Malcolm Merlyn but Supergirl doesn't know him that he portrays the character. He also claimed that this episode is a creation of a couple of musicals put together and very much like "Romeo & Juliet." The musical episode were all just existing in their heads, none of it was real and it is really bizarre.

Meanwhile, Valdes also commented that Darren Criss who will be playing Music Meister is his colleague in college. Which he bring them into illusory that will take place in their own heads and pull the idea of Barry and mom used to bond over musicals, as per Spoilers Guide.

The next episode of "The Flash" and "Supergirl" is proving that musicals are not just escapism. But also an emotional catharsis. So, everyone are asking whether they can finally see Winn and Cisco for the first time?

Valdes address the interaction but sadly, the answer is no. Though Cisco stated that Winn and he will be playing a lot in an alternate reality, but J'onn J'onzz and Mon-El will be bringing Kara back to Earth 1.