DC's Legends of Tomorrow gets the task of ending the Invasion! crossover between all four Arrowverse shows on The CW. It all began in Supergirl, when Barry Allen (Grant Gustin) and Cisco Ramon (Carlos Valdes) showed up on Earth-38 to bring Kara (Melissa Benoist) to their earth to help fight the Dominators.
As we learned in The Flash, the race of aliens first showed up on earth in the 1950s, but returned today. At the end of The Flash, Oliver Queen (Stephen Amell), John Diggle (David Ramsey), Thea Queen (Willa Holland), Sara Lance (Caity Lotz) and Ray Palmer (Brandon Routh) were abducted by the Dominators. During the 100th episode of Arrow, they were forced to live through a shared hallucination of what their lives would be like if Oliver didn't become Green Arrow. During their escape from the Dominators' ship, they were saved by the Legends' timeship, the Waverider. Unfortunately, they learned that the Dominators have a giant weapon and are heading straight for earth.
Click through for a preview of the final episode of Invasion!, which airs on The CW at 8 p.m. ET. (Photo: Diyah Pera/The CW)