Manage episode 167529341 series 107091
Barry investigates a meteor crash outside Central City that turns out to be a spaceship from which aliens emerge. Lyla tells the team that the "Dominators" landed previously in the 1950s, but then mysteriously departed. Needing help, Barry assembles the original Team Arrow, Thea, the Legends, and Supergirl of Earth-38. The team begins training at a S.T.A.R. Labs facility, sparring against Supergirl to prepare against the aliens. Cisco finds and reveals a message to Rip Hunter from Barry's future self, which exposes Barry's manipulation of the timeline and how it affected other team members. Oliver, Supergirl, Felicity, Martin and Jefferson become the only ones who still trust Barry. The Dominators abduct the President. Supergirl leads most of the others in a rescue effort, but the Dominators kill the President and trap them with a mind control device. The controlled heroes return and attack S.T.A.R. Labs. While Oliver holds them off, Barry lures Supergirl to the device and manipulates her into destroying it, freeing everyone. The team decides to trust Barry again. Suddenly, Sara, Ray, Diggle, Thea, and Oliver are teleported away before Barry can intervene.
This episode begins a crossover that continues on Arrow season 5 episode 8 and concludes on Legends of Tomorrow season 2 episode 7.