After numerous attempts in many different time periods, the team has successfully captured Vandal Savage. However, Savage tells Kendra that he can reunite her with Carter so she struggles with whether she should kill him. Rip decides they will deliver Savage to the Time Masters which doesn’t sit well with Snart and Rory. The duo decides it may be time to jump ship and return to their old life. Meanwhile, Savage taunts Ray about his place in Kendra’s life.

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).

The Legion of Doom rewrites history after obtaining the Spear of Destiny, potentially changing the Legends forever.

Barry and Iris's wedding brings the gang together, but things go awry when villains from Earth-X attack the ceremony. All of the superheroes band together with help from their super friends like Citizen Cold, The Ray, Felicity Smoak, Iris West and Alex Danvers to take on their most formidable villains yet. Earth's mightiest heroes - Green Arrow, Supergirl, The Flash and White Canary - lead their teams into battle to save the world.

The crossover starts on Supergirl S03E08 Crisis on Earth-X (I), Arrow S06E08 Crisis on Earth-X (II) and The Flash S04E08 Crisis on Earth-X (III).