It was late 2017. If you were watching The CW back then, you knew something massive was coming, but nobody really expected a four-hour wedding-crashing epic involving interdimensional Nazis. Seriously. Crisis on Earth-X didn't just raise the bar for superhero television; it basically broke the scale. While most crossovers feel like a forced marketing gimmick to get viewers to jump from one show to another, this one felt like a cohesive, high-stakes movie that just happened to be split across Supergirl, Arrow, The Flash, and Legends of Tomorrow.
Most fans remember the big stuff. The wedding of Barry Allen and Iris West getting interrupted by a laser blast. The sight of an evil Oliver Queen. But when you look back at it now—years after the Arrowverse has mostly wound down—you realize it was the last time the franchise felt truly dangerous.
What Crisis on Earth-X Got Right (And Why It Still Holds Up)
The premise is wild. In the DC Multiverse, there’s a 53rd world called Earth-X. It’s a "nightmare scenario" world where the Nazis won World War II. Honestly, it's a trope as old as comic books themselves, but the execution here was surprisingly grim for network TV. We weren't just seeing generic villains; we were seeing "Dark Arrow" (Oliver’s doppelgänger) and "Overgirl" (Kara’s doppelgänger).
What made this work wasn't the spectacle. It was the contrast.
You have the lightness of a rehearsal dinner—Barry and Oliver sharing a drink, Kara singing "Runnin' Home to You"—juxtaposed against the sheer coldness of their counterparts. It’s jarring. The stakes weren't just "save the city." They were deeply personal. Overgirl was dying, and the only way to save her was to steal the heart of the Multiverse's ray of sunshine: our Kara Zor-El.
The Logistics of a Four-Show Juggernaut
Ever wonder how they actually filmed this? It was a nightmare.
The production involved four different stunt teams, four separate writers' rooms, and a filming schedule that required actors to jump between sets across Vancouver. According to Marc Guggenheim, the executive producer who basically architected the whole thing, the goal was to treat it as a single four-hour block. They even changed the title cards for each show to a unified "Crisis on Earth-X" logo. This was a first. Usually, Supergirl felt like its own thing, but here, the narrative thread didn't snap once.
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The Death of Martin Stein: A Moment That Changed Everything
We have to talk about Victor Garber.
If there’s one moment that defines this crossover, it’s the death of Professor Martin Stein. It’s heartbreaking. I mean, genuinely, "ugly-cry" territory. For years, Stein and Jax (Franz Drameh) were the "Firestorm" duo, the heart of Legends of Tomorrow. Stein’s sacrifice to open the portal so the heroes could escape Earth-X wasn't just a plot point—it was the end of an era.
The scene in the Waverider med-bay where Stein tells Jax he needs to let him go so Jax can live? That’s peak writing. It’s a 2-word punch to the gut: "Stay alive."
Most superhero shows shy away from killing off major characters in crossovers because it complicates the individual shows' schedules. But Crisis on Earth-X leaned into it. It proved that the Multiverse has consequences. It’s not just a playground.
Breaking Down the "Earth-X" Versions of Our Heroes
The "villains" weren't just shadows. They were reflections of the heroes' worst impulses.
- Dark Arrow: This wasn't just a guy in a mask. He was the Führer of Earth-X. Stephen Amell played him with this terrifying, rigid stillness that was the exact opposite of the brooding-but-kind Oliver we knew.
- Overgirl: Melissa Benoist had to play a version of Supergirl who believed in genetic purity and absolute power. It’s weird seeing Kara’s face twisted into that kind of sneer.
- Eobard Thawne: Tom Cavanagh returned as the Reverse-Flash. Because of course he did. Thawne is the ultimate cockroach of the Arrowverse; he always finds a way back. His inclusion here linked the threat back to Barry’s personal history, making it more than just a multiversal invasion.
The interesting thing is that the Earth-X villains actually loved each other. Dark Arrow’s motivation for the entire invasion was saving his wife (Overgirl). It’s a twisted mirror of Barry trying to marry Iris. Love is the motivator on both sides, which is kinda messed up if you think about it too long.
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The Technical Feats and That Iconic Bridge Fight
The action choreography in the final hour was insane. There’s a specific shot—a long, sweeping take during the final battle on the bridge—where almost every hero gets a moment to shine. Black Canary, Wild Dog, Vixen, The Ray, Citizen Cold, Heat Wave. It’s a lot.
Usually, when you have 20+ superheroes on screen, it looks like a messy backyard brawl. The CGI gets muddy. The lighting goes weird. But the directors managed to keep the focus sharp.
- The Ray: This crossover introduced Russell Tovey as Ray Terrill. A gay superhero from Earth-1 who ended up leading the resistance on Earth-X.
- Citizen Cold: We got a version of Leonard Snart (Wentworth Miller) who was actually a hero. Seeing him and the Ray together added a layer of representation that felt organic to the story of fighting a regime built on hate.
Why "Crisis on Infinite Earths" Didn't Quite Beat It
Look, Crisis on Infinite Earths was bigger. It had Kevin Conroy as Batman and Brandon Routh back as Superman. It had Ezra Miller’s Flash meeting Grant Gustin’s Flash. But bigger isn't always better.
Crisis on Earth-X felt more intimate.
The smaller scope allowed for better character moments. You had Alex Danvers and Sara Lance bonding over a one-night stand and their shared trauma. You had the heartbreaking realization that Earth-X’s version of Tommy Merlyn was a monster. These are the things that stick with you. Infinite Earths got bogged down in the "math" of the Multiverse and the "Anti-Monitor" being a giant CGI cloud. Earth-X gave us faces we recognized—and feared.
The Legacy of the 2017 Crossover
Even now, people talk about the "double wedding" at the end. Some fans hated it. They felt Felicity Smoak "hijacked" Barry and Iris’s moment by suggesting a spontaneous double ceremony. Honestly? It was a bit much. But it was also very "Arrowverse." These shows were always part soap opera, part comic book. Ending a war against interdimensional Nazis with a quiet park wedding is basically the most CW thing to ever happen.
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But beyond the romance, the crossover cemented the idea of the "Multiverse" for mainstream TV audiences before Marvel's MCU really started digging into it with Loki or Spider-Man: No Way Home.
Actionable Takeaways for Fans Re-watching in 2026
If you’re planning a re-watch, don’t just hit the highlights. To get the full experience, you have to watch the episodes in the specific order they aired, regardless of which "season" they belong to in your streaming library.
- Start with Supergirl Season 3, Episode 8. This sets the emotional stakes and the wedding backdrop.
- Move to Arrow Season 6, Episode 8. This is where the villains' true plan is revealed and the "Earth-X" prison sequence happens.
- Continue with The Flash Season 4, Episode 8. This contains the core of the resistance fight and the most significant character deaths.
- Finish with Legends of Tomorrow Season 3, Episode 8. This is the big final battle and the emotional fallout.
Final Perspective
Crisis on Earth-X wasn't perfect. The CGI for the "Waverider" in some shots looks a bit dated now, and the Nazi imagery can be uncomfortable for some viewers. But as a piece of television history? It's a miracle it exists at all. Getting that many actors, schedules, and budgets to align for a four-hour event is something we might not see again for a long time.
It reminded us that heroes aren't defined by their powers, but by their choices. Oliver Queen could have been a dictator. Kara Zor-El could have been a conqueror. They chose to be something else.
If you want to see the Arrowverse at its most confident, most daring, and most heartbreaking, this is the one. Skip the fluff and go straight to the bridge fight. It still rips.
Next Steps for Your Arrowverse Marathon:
Check the specific "Multiverse" reading order if you want to see how the Earth-X comics differ from the show. The Freedom Fighters have a much deeper history in DC lore than the crossover had time to explore. You might also want to look up the "Freedom Fighters: The Ray" animated series on CW Seed (or wherever it’s streaming now), which serves as a spiritual prequel to the event and gives more context on why Earth-X is the way it is.