Time Master Rip Hunter puts together his diverse team to fight immortal villain Vandal Savage who is on the verge of destroying humanity in 2166.

When a malfunction sends the Waverider crashing into 2046 Star City, our heroes face a startling version of their own future where they never stop Savage and never return home. The city is in ruins and overrun by criminals, which thrills Rory. Sara is despondent over the destruction of her home and stunned when she learns what happened to her old friend, Oliver Queen.

Dr. Nate Heywood, an unconventional historian, makes a shocking discovery. Nate then seeks out Oliver Queen for help to find the scattered Legends. Once reunited, they try to protect Albert Einstein from being kidnapped before the Nazis destroy New York City with a nuclear bomb. Meanwhile, Ray notices that Sara has a mission of her own, which leads them both to face her nemesis, Damien Darhk.

After learning the Dominators’ plan for the world, the Legends must work together with The Flash, Supergirl and Green Arrow to kill them once and for all. Meanwhile, Stein figures out, with the help of others, how the team can terminate the Dominators, but is distracted by the aberration he realizes he created in 1987.

The crossover starts on Supergirl S02E08 Medusa (I), The Flash S03E08 Invasion! (II) and Arrow S05E08 Invasion! (III).