After Zoom unleashes an army of Earth-2 meta-humans on Central City, Flash is shaken when he sees their leader is the Black Canary’s Earth-2 doppelgänger
With Flash gone, the team must figure out a way to handle the return of Girder, an old enemy. Meanwhile, Barry fights to return to his old life.
On Earth-2, the Flash team races to find Zoom’s lair and seeks help from the most unexpected source. Meanwhile, back on Earth-1, Caitlin rushes to perfect Velocity-9 so Jay can stop the Geomancer.
Flash, Wells and Cisco travel to Earth-2 to rescue Wells’ daughter from Zoom, and encounter Killer Frost and Deathstorm.