Duet (The Flash)
"Duet" is the seventeenth episode of the third season of The CW television series The Flash, which aired on March 21, 2017. It was written by Aaron Helbing and Todd Helbing from a story by Greg Berlanti and Andrew Kreisberg, and was directed by Dermott Daniel Downs. The episode features a musical crossover with Supergirl and reunites Grant Gustin and Melissa Benoist with their former Glee co-star Darren Criss, who portrays the Music Meister. Jesse L. Martin also reunites with Jeremy Jordan, with whom he previously worked in the 2012 musical film Joyful Noise.
The story begins at the end of the Supergirl episode "Star-Crossed", which aired on March 20, 2017. The episode sees Kara Danvers / Supergirl being hypnotized into a coma by the Music Meister, with Mon-El and J'onn J'onzz / Martian Manhunter bringing her to Earth-1 in hope that Team Flash can save her.
Plot
J'onn J'onzz and Mon-El of Earth-38 arrive on Earth-1 with a comatose Kara Danvers, in hope that Barry Allen and his team can revive her. They warn Barry that the escaped prisoner Music Meister is coming for him too. Meister attacks and places Barry in a similar coma.Barry wakes up to find himself without his powers in a musical dream world where he discovers Kara singing in a nightclub and where everyone resembles people they know in the real world. Meister tells Kara and Barry that if they follow the script, they will return to the real world. He warns them, however, that if they die in the dream world, they die in real life.
Barry and Kara are forced to work as singers in a nightclub run by gangster Cutter Moran. Cutter's rivals Digsy Foss and his unnamed husband have their men kidnap Barry and Kara and tell them to find their daughter, Millie Foss, whom they believe is being held hostage by Cutter. Barry and Kara find Millie in a forbidden relationship with Cutter's son Tommy Moran. They convince the pair to reveal their love, which helps Barry and Kara to realize their own mistakes. Digsy, his husband, and Cutter seemingly give their approval, but subsequently decide to go to war.
Meanwhile in the real world, Meister is revealed to have been stealing Barry and Kara's powers, using them to rob a bank. Cisco Ramon, Wally West, and J'onn arrive to fight Meister. They defeat him and lock him up in a S.T.A.R. Labs cell.
Back in the musical reality, Barry and Kara prepare to sing an original song to appease Cutter, but the gang war begins outside. Barry and Kara are shot in the crossfire and are dying, but Cisco, Mon-El and Iris enter the dreamworld to save them, allowing Barry and Kara to admit their love for Iris and Mon-El respectively.
They wake up in S.T.A.R. Labs. Meister escapes his cell, revealing to Barry and Kara that he just wanted them to realize their love before leaving. Kara, J'onn and Mon-El return to Earth-38 while Barry and Iris move back in together. Barry serenades and re-proposes to Iris, who accepts.
Production
Casting
Main cast members Grant Gustin, Candice Patton, Danielle Panabaker, Carlos Valdes, Keiynan Lonsdale, Tom Cavanagh, and Jesse L. Martin star as Barry Allen / Flash, Iris West, Caitlin Snow, Cisco Ramon / Vibe, Wally West / Kid Flash, Harrison Wells, and Joe West, respectively. In January 2017, Darren Criss was cast as Music Meister. Additionally, the episode's guest cast includes Melissa Benoist as Kara Danvers / Supergirl, David Harewood as J'onn J'onzz / Martian Manhunter and Chris Wood as Mon-El, reprising their roles from Supergirl, along with Legends of Tomorrow actor Victor Garber, Supergirl actor Jeremy Jordan, and John Barrowman from Arrow and Legends of Tomorrow playing different roles.Filming
Filming of the episode occurred from February 1 until February 15, 2017, and was directed by series veteran Dermott Daniel Downs.Music
In January 2017, Rachel Bloom revealed that she had penned an original song for the episode, which was titled "Super Friends", and was set to be sung by Gustin and Benoist. Bloom explained that, "as soon as I heard that they were doing a musical crossover, I e-mailed Mark Pedowitz who connected me to Greg and Andrew . I immediately offered them my services. As soon as they picked one of my song ideas, I hopped on the phone with my old Robot Chicken boss Tom Root and... based on that brainstorm, I wrote up the song 'Superfriends'. I am so excited to contribute more to the upward trend that is musicals in television and film. Music can be one of the most amazing and efficient forms of storytelling and character development. Also, it was really fun to write a comedy song for two superheroes." The song was later retitled "Super Friend".Additionally, Benj Pasek and Justin Paul, winners of the Academy Award for Best Original Song for writing the lyrics for "City of Stars" in La La Land, were the authors of another song written for the episode, "Runnin' Home to You", which was performed by Gustin. Kreisberg commented, "Benj and Justin are the premiere songwriting duo of our time... To have them be a part of our musical episode is beyond our wildest expectations. We hope everyone falls in love with the song they wrote for us as much as we did."
A soundtrack album for the episode, titled The Flash – Music from the Special Episode: Duet, was released on March 22, 2017, through WaterTower Music.