The Flash
Season 3 Episode 17 - Duet (II)
Barry and team are surprised when Mon-El and Hank Henshaw arrive on their Earth carrying a comatose Supergirl who was whammied by the Music Meister. Unable to wake her up, they turn to Team Flash to save her. However, the Music Meister surprises The Flash and puts him in a similar coma, one that Team Flash can't cure. Kara and Barry wake up without their powers in an alternate reality where life is like a musical and the only way to escape is by following the script, complete with singing and dancing, to the end. The crossover starts on Supergirl S02E16 Star-Crossed (I).
Episodes in Season 3
Flashpoint
42 min
Paradox
42 min
Magenta
42 min
The New Rogues
42 min
Monster
42 min
Shade
42 min
Killer Frost
42 min
Invasion! (II)
42 min
The Present
42 min
Borrowing Problems from the Future
42 min
Dead or Alive
42 min
Untouchable
42 min
Attack on Gorilla City (1)
42 min
Attack on Central City (2)
42 min
The Wrath of Savitar
42 min
Into the Speed Force
42 min
Duet (II)
43 min
Abra Kadabra
42 min
The Once and Future Flash
42 min
I Know Who You Are
42 min
Cause and Effect
42 min
Infantino Street
42 min
Finish Line
42 min