While trapped in The Music Meister’s fantasy, Kara and Barry will also be seeing some familiar faces.
Based on what we know about ‘Duet’ already, it seems the hand controlling the marionette would belong to The Music Meister.
Not only is he controlling the heroes by trapping them in the fantasy, but also by making them participate.
Supergirl continues with ‘Star-Crossed’ on Monday, March 20 at 8 p.m. EST, followed by The Flash on Tuesday, March 21 in the same time slot with ‘Duet’.