Breaking Down the Arrowverse 4-Way Crossover Event Episode Synopses

Joseph Wilbur
TV Comics
TV Comics

Over the course of the past few weeks, The CW has given us several teasers for the upcoming four-way Arrowverse crossover. However, with less than two weeks until the crossover airs, details are finally starting to flow in. In the past few days, we finally got our first glimpse of the big bad villains of Invasion!, and now The CW has finally released the synopses for all four of episodes, starting with the Supergirl episode titled “Medusa” airing on November 28.

For the full synopses, you can check them out here, but here’s our breakdown of each episode’s synopsis.

Supergirl: “Medusa”


Don’t expect to see the meet-up in the above image to occur too soon. The kick off of this exciting Heroes vs. Aliens showdown will not begin until the end of the Supergirl episode on November 28. What will we see of the Invasion! in this episode? The crossover will kick off with Barry Allen and Cisco Ramon making a multiverse crossing trip to Supergirl’s Earth. The two heroes will be seeking Kara’s assistance in protecting their Earth from an incoming alien invasion. Will we find out what those gauntlets we see on Cisco Ramon are for?

In the front end of the episode, we will find the D.E.O., aided by Lena Luthor ward off a deadly alien virus released by CADMUS. We will also see Alex come out to her mother, and will Kara finally hear the truth about the Guardian?

The Flash: “Invasion!”

The Flash Season 3, Episode 8 - "Invasion" (L-R) Grant Gustin as The Flash, Stephen Amell as Green Arrow and David Ramsey as John Diggle

Wait, so how did Barry and Cisco make it to Supergirl’s Earth to recruit her? From what we gather from the Flash episode synopsis, we will have a bit of a “rewind” to set up Barry and Cisco’s trip across the multiverse. In the rewind, we will see the Dominators attack on Central City. With Barry unable to protect the city from this deadly Invasion!, he starts by recruiting Green Arrow, and the two hunt down the Legends of Tomorrow team. When finally all of the “super friends” are together, we’ll see them come up with a plan to defeat the aliens.

But there is more. The synopsis says that “a shocking secret” is revealed that sets everyone against each other, unable to know who they can trust. What secret can possibly rock the world’s greatest heroes faith in each other?

Arrow: “Invasion!”


Something’s definitely off about Arrow‘s 100th episode, and this synopsis seems to raise the most questions. For starters, Laurel is Oliver’s loving fiancee, and he never got on the Queen’s Gambit. His parents are both well, but Oliver questions this new reality. Is this the result of time travel? Are the Dominators warping with Green Arrow’s mind?

Our next question is raised when we find out that Felicity, Barry, and Kara take on a new threat. Is this new threat different than the Dominators? Hopefully, all of these questions will be answered in Arrow‘s 100th episode.

Legends of Tomorrow: “Invasion!”


The final episode of the four-way Arrowverse crossover, this synopsis reveals that our heroes finally learn the Dominator’s plan for the world. This raises the question of what is the Dominator’s final goal for the planet Earth?

As the team comes up with a plan to kill off the Dominators once and for all, it seems that Martin Stein is the one that finally figures out a way to destroy the masterminds of the Invasion! However, Stein is said to be distracted by an aberration he created in 1987. Wondering what an aberration is? Typically, it means ‘something abnormal,’ but when dealing with time travel, who knows what Stein’s creation is.

When to Watch the Arrowverse Crossover?

Tune in to watch the four-way Arrowverse Invasion! crossover on the CW on the following nights:

  • Supergirl on Monday, Nov 28
  • Flash on Tuesday, Nov 29
  • Arrow on Wednesday, Nov 30
  • Legends of Tomorrow on Thursday, December 1
  • Supergirl (again) on Monday, December 5
Joseph Wilbur
Joseph Wilbur was a former writer for Fandom for over 2 years. He primarily wrote about the Arrowverse shows, or the DC and Marvel universes. He is a Star Wars fanatic, and has read every book in the 'Star Wars Legends' Universe (most of them at least twice).
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