It's time for a crossover and that too a musical one. A new trailer of "The Flash" and "Supergirl" musical crossover has been released and fans couldn't be more excited.

As per TV Line, "The Flash" star Grant Gustin will team up with Melissa Benoist, who plays Supergirl. They will bring in their singing talents in the upcoming "The Flash" musical episode, "Duet.".

The event of the crossover will kick off at the end of "Supergirl" episode "Star-Crossed" on Monday, March 20. The Music Meister, played by Darren Criss, will put Supergirl in a coma. 

Mon-El and Hank then travel to "The Flash", carrying a comatose Supergirl. This crossover episode will take place on March 21. The summary of the crossover episode stated that Mon-El and Hank are unable to wake the comatose Supergirl. Finally, they turn to Team Flash to save her. But plans go awry when the Music Meister puts The Flash in a similar coma.

The crossover takes place when Kara and Barry wake up in an alternate reality. They don't possess their super powers and the life in this AU is like a musical. The only way to escape from this universe is to play the part, which requires them to singing and dancing. 

The special episode will also feature Jesse L. Martin as Joe, Victor Garber as Dr. Stein, John Barrowman as Malcolm Merlyn, Jeremy Jordan as Winn and Carlos Valdes as Cisco. However, fans are excited to learn that actress Teri Hatcher has been cast in a villainous mystery role in "Supergirl".

According to Mashable, "Lois & Clark" actor Dean Cain, who played Superman in the 90s series, appeared on "Supergirl" as Jeremiah Danvers for four episodes. Now Hatcher, who played Superman's love interest Lois, is also guest-starring in the CW series.

Executive producers Andrew Kreisberg stated that there is a chance of a "Lois and Clark" reunion in "Supergirl". "We'd love to. They would love to. There's a plan, Mashable quoted Kreisberg. "There's always a plan, if we can execute the plan."

Kreisberg added that he has known Cain for quite some time now and will now get to know Teri Hatcher through "Supergirl". Hatcher knows how important it is for the fans when they will see her in "Supergirl", thus she is appearing in the series for them.