Barry and Supergirl team up once again on The Flash Season 3 Episode 17 "Duet."
But they won't be able to use their speed and might to battle the Music Meister.
They're going to have to rely on their singing and dancing instead.
The video promo below explains a few of the rules in their new reality. Barry and Kara must stick to the script if they want to get out alive.
And they're not alone in the movie musical. Several familiar faces from their shared universes pop up to lend their musical talents.
Press play on the video and let us know what you think will happen on "Duet."
Need to catch up? You can watch The Flash online anytime!