At long last, "The Flash" and "Supergirl" will offer Broadway stars Jesse L. Martin and Victor Garber an opportunity to sing together -- but that's not all. In the musical crossover episode between the two DCTV shows, the two actors will take on new roles, one as a mobster and the other as his partner. According to TVLine, who was able to preview the crossover episode, Martin and Garber will play the fathers of Candice Patton's character Millie.
“That’s one of the cool things about ['The Flash'] — just when you think you’ve settled into the character that you’d originally been given, all of a sudden they find a way to give you something else to do,” Martin said of his upcoming musical role.
On "The Flash," Martin usually plays Barry's adoptive father Joe West, while Garber is Professor Martin Stein (half of Firestorm) on "DC's Legends of Tomorrow." The musical crossover, however, takes place in the Music Meister's dream world. The episode finds both Barry and Kara comatose thanks to the Music Meister, who creates this alternate reality for them. In this alternate reality, they are at Music Meister's mercy; they must follow his script -- or die.
Though Barry and Kara are aware of their roles, the other supporting characters won't be. Martin and Garber will play as-yet-unnamed mobsters, whose daughter Millie is in love with Chris Woods' Tommy, a rival mob boss' son. It seems, then, that Iris' fathers won't approve of her new boyfriend; according to Patton, the musical crossover will find them “fighting for their love, because their families don’t want them to be together."
This will present something of a quandary for Barry and Kara, who are in love with Iris and Mon-El respectively. “Music Meister is almost a sadistic, wannabe Cupid,” explained "Supergirl" star Jeremy Jordan.
“The Flash” and “Supergirl” musical crossover will start with a lead-in scene on the March 20 episode of “Supergirl,” and continue in full on the March 21 episode of “The Flash.” The episode will include musical numbers from “The Flash” stars Grant Gustin, Jesse L. Martin and Carlos Valdes; “Supergirl” stars Melissa Benoist and Jeremy Jordan; and “Legends of Tomorrow” co-star Victor Garber and “Arrow” regular John Barrowman; along with “Glee” alum Darren Criss as the Music Meister, the episode’s antagonist.