Mon-El's parents arrive to bring home and help restore Daxam to its former glory... and Supergirl realizes that Mon-El has been lying to her. Meanwhile, Winn discovers that Lyra has set him up when he's the prime suspect in a museum robbery. The Music Meister puts Supergirl into a coma and the story line concludes in The Flash: "Duet", Season 3, Episode 17.

Lena's ex, Jack Spheer, arrives in National City to roll out a new nanite medical procedure. However, Kara soon realizes that something more is going on when one of the human test subjects die under mysterious circumstances. Meanwhile, Lyra comes between Winn and James in their crimefighting efforts.