'Arrow,' 'The Flash,' 'Supergirl' And 'Legends Of Tomorrow' Crossover Spoilers: Barry And Cisco Bring Kara To Earth-1 In New Sneak Peek

A new sneak peek from the upcoming crossover event between "Arrow," "The Flash," "Supergirl" and "Legends of Tomorrow" shows how Kara (Melissa Benoist) finds her way to Earth-1 to join the battle against the alien race Dominators.

In the clip exclusively shared by Entertainment Weekly, a breach opens in an airplane hangar where several characters from "Arrow," "The Flash" and "Legends of Tomorrow" are assembled. Barry (Grant Gustin) and Cisco (Carlos Valdes) then come out from the breach with Kara in tow.

After seeing Kara for the first time, Oliver (Stephen Amell) asks Barry, "I thought you're bringing an alien?"

"Yeah, we did," Barry replies, before introducing the Kryptonian to the team. "Everybody, this is my friend Kara Danvers or as she's known on her Earth, Supergirl."

When Jax (Franz Drameh) asks what's so super about her, Kara flies up into the air and uses her heat vision to draw the House of El emblem on the ground. Thrilled by what everybody just saw, Felicity (Emily Bett Rickards) says, "Best team-up ever!"

The four-night crossover event kicks off with Season 2, episode 8 of "Supergirl." The synopsis for the episode reveals that Barry and Cisco travel all the way to Kara's Earth to seek her help in defeating the Dominators trying to invade their Earth.

The story continues in Season 3, episode 8 of "The Flash," where Barry speeds over to Star City to ask Oliver for help in stopping the Dominators from their plan to eliminate all metahumans on Earth. After realizing the battle against the aliens is bigger than they thought, they track down the Legends for assistance. But when the whole team comes up with a plan to attack, a shocking secret related to the Flashpoint timeline is revealed.

The team tries to take down the Dominators in Season 3, episode 8 of "Arrow" to no avail. But in Season 2, episode 7 of "Legends of Tomorrow," Stein (Victor Garber) — with the help of others — figures out how they can defeat the Dominators. The experienced physicist, however, is distracted by the time aberration he created in 1987.

The crossover event will air from Nov. 28 to Dec. 1 at 8 p.m. EST on The CW.