In The Flash Season 3 episode 17, “Duet,” Music Meister takes out Supergirl and The Flash, which forces Kid Flash, Martian Manhunter, Vibe and Mon-El to step-up in their absence.
The Flash Spoilers ahead.
On Earth-38, Music Meister “whammies” Supergirl into a coma so he can steal Winn’s breach technology and use it to travel to Earth-1. Before he left, he told Martian Manhunter he was after the fastest man alive. Winn and Martian Manhunter decided to bring Supergirl to Earth-1 to warn The Flash.
Music Meister says he wants to teach everyone a lesson and does the same hypnotizing thing to The Flash, which also puts him in a coma. The team at Star Labs figures out Music Meister’s power is to steal abilities from others. Now he has superspeed, flight, super strength and heat vision. It’s now up to Kid Flash, Vibe, Mon-El, and Martian Manhunter to stop him. Cisco uses his vibes to help Kid Flash and Martian Manhunter catch Music Meister off guard. Kid Flash has an awesome CGI moment as he tackles Music Meister to the ground.
Melissa Benoist performs “Moon River”
Meanwhile, Supergirl and The Flash are stuck in a ‘musical’ world where they don’t have their powers. Malcolm Merlyn, Martin Stein, Joe West, Winn, Mon-El, Iris and Cisco are all there, but with different names.
Jeremy Jordan, Carlos Valdes, John Barrowman and Darren Criss perform “Put A Little Love In Your Heart”
Malcolm Merlyn's character, Cunner Moran, is a gangster who owns a club where Supergirl and The Flash are paid to perform. Malcolm Merlyn and Joe West, who is basically the mayor of the town, are adversaries. Joe’s daughter, who is named Millie (actually Iris), is missing and he asks Flash and Supergirl to help. Cisco’s character, named Pablo, shows them to Millie’s apartment where they find she and Mon-El’s character, named Tommy Moran (Malcolm Merlyn’s son), making out. Since their fathers hate each other, they are hiding their relationship, but Supergirl and Flash convince them to tell the truth because they are still feeling guilty about mistakes in their own relationships with Mon-El and Iris.
Victor Garber, Jesse L. Martin and John Barrowman perform “More I Cannot Wish You”
Millie refers to Stein and Joe as her daddies, and while they say they support her decision to be with Tommy Moran, they immediately call a war on Cunner Moran. The battle between the two that results in Flash and Supergirl getting shot.
Grant Gustin and Melissa Benoist perform “Super Friend”
Back at Star Labs, Music Meister has a conversation with Mon-El and Iris. He tells them they can only save Kara and Barry if their love is strong enough. Cisco realizes he can vibe inside Kara and Barry's head. They arrive just as Barry and Kara get shot and bring them back to Earth-1. #WestAllen is back together again and Barry believes in their love so much that he asks Iris to get married by singing her a special song. She, of course, says yes. Yay happily ever after.
Grant Gustin performs “Runnin Home To You”
The musical performances in “Duet” are available to purchase now on Apple Music and Spotify.
