The last time you saw The CW’s Supergirl, The Flash, Arrow and DC’s Legends of Tomorrow, they were working together defending Earth-1 against alien invaders.
Check out the trailer above for The Flash and then tune into the full episode Tuesday at 8 p.m. ET.
And in case you missed the recent Invasion! Heroes vs Aliens crossover event, you can watch all four episodes on cwtv.com or The CW app.