INVASION!

PT 1 > FLASH: SEASON 3 (2016)
Flash encounters an alien ship, from which spring hordes of Dominators intent on conquering Earth.

PT 2 > ARROW: SEASON 5 (2016)
The Dominators capture Green Arrow and the Legends, and mind-probe them on board their ship.

PT 3 > LEGENDS OF TOMORROW: SEASON 2 (2016)
The final free-for-all, as the Legends, team Flash, Supergirl and Green Arrow take on the Dominators.