The Flash: Easter Eggs and Other Things You Might Have Missed In "Invasion!"

INVASION!

Back before DC and Marvel had annual crossover events, the idea was pretty rare. One of the first big ones at DC was Invasion!, which brought together numerous dangling plot threads from books like Legion of Super-Heroes and Omega Men while bringing Earth under its first major alien invasion since 1986's continuity reboot, Crisis on Infinite Earths.

This meant that numerous alien races represented in the Invasion! storyline had little or no history with Earth and the world's superheroes at this point in the storytelling: Daxamites came to Earth and quickly learned that they had powers under Earth's yellow sun, the Dominators hadn't fought anybody yet (although they had already squared off with the Legion, that wasin the far-flung future), and on and on.

So in a lot of ways, the Invasion! on TV is much like the Invasion! in the comics: this whole thing of an alien attack was new for everybody.

There are a lot of things that happened in Invasion! that either can't, won't, or are wildly unlikely to happen in this one (such as the death of Wally West's father or the activation of a ton of characters' metagenes, including Snapper Carr and Maxwell Lord), but the gist of it was kind of genius in that most of the story didn't heavily feature the heavy hitters of the DC Universe (although they all played a role in their own crossover stories). So you can swap most of the characters in and out and still tell materially the same tale.

RIDLEY SCOTT

"Enough to give Ridley Scott nightmares" is how Barry describes the Dominators after he first encounters them.

That, of course, is a reference to the filmmaker responsible for rewriting the way a lot of people think about aliens with the Alien film franchise.

Ironically, Scott's most recent Alien film is Prometheus, which shares a name with this season's big bad on Arrow.

VIGILANTE

Worth a note, since this is the first time he's been seen on The Flash.

Vigilante -- in the comics, District Attorney Adrian Chase -- is a brutal, Punisher-like antihero who has recently taken up residence in Star City.

In the last episode of Arrow, he and Oliver got into it over methods, with Vigilante saying that he doesn't trust Oliver's no-kill policy.

That was him who was trying to take out Oliver and Diggle -- who were apparently hunting him instead of bad guys, which is a good way to get an unhinged antihero angry at you.

THE HALL OF JUSTICE

If that old STAR Labs facility being used to headquarter the heroes of the Invasion! crossover on tonight's episode of The Flash looked familiar, there's a reason for that: it's the Hall of Justice.

Originally created for the Superfriends cartoons of the '70s and '80s, the Hall of Justice was the home base for the Justice League, although this is the building's first appearance in live action.

There were several establishing shots using the building, and one has to wonder: will this be a setting reserved for crossovers, or might it turn out to be the new home for Team Flash, since Barry and H.R. Wells keep talking about making the existing STAR Labs facility open to the public (a new career opportunity since Barry left the Central City Police Department at the end of last week)?

Ironically, the Hall of Justice was originally drawn by Al Gmuer, background supervisor for Hanna-Barbera, who modeled it on the art deco Union Terminal in Cincinnati, Ohio -- a train station turned museum.

"We were talking about where to put it—we were talking about maybe it was an old warehouse or whatever," Marc Guggenheim told reporters during a screening of the crossover on Monday. "Someone said something that made me think, 'You know, there's this building in Cincinnati that is the basis for the Hall of Justice in the Super Friends. I'm sure there's stock footage that we could then alter.' That's what we ended up doing. I was so giddily happy. It's probably my favorite thing in the whole crossover: the Hall of Justice. Props to Encore who did an amazing job of altering it in all the right ways. Putting the waterpool in the front and the sculptures ... 10-year-old me can die happy."

EARTH-38

While the designation of Supergirl's Earth as "Earth-38" might seem like a pretty clear reference to Superman's first appearance in 1938, a Supergirl production staffer told ComicBook.com during a set visit that's not the case.

What was it meant to reference?

...Well, this was after-hours chatter, not a real interview, so we weren't recording and can't remember. It has something to do with CBS. The joke being that Supergirl takes place on "Earth-CBS."

What is Earth-38 in the comics? Recently reinvented for The Multiversity, here's how DC describes it:

The citizens of Gotham and Metropolis have learned to rely on Superman and Batman at all times, whenever villainous foes pose a threat to peace and prosperity. They are a constant. They are eternal.

But on Earth-38, time moves as it does on Earth-Prime, ceaselessly forward, whether you are simply human or super-human. In this world, Superman first appeared to the public in 1938, and Batman followed one year later in 1939. From that point on, Clark Kent and Bruce Wayne proceeded to age normally, growing old and eventually leaving the super heroics to their sons, daughters and grandchildren.

Modern citizens of Earth-38 are familiar with a whole dynasty of heroes following in the footsteps of the original Batman and Superman. This includes Kara Kent, the daughter of Clark Kent and Lois Lane, who would go on to develop her own super powers and fight injustice as Supergirl. The title of Batman, taken on after Bruce Wayne's retirement by the original Robin, Dick Grayson, is eventually passed down to Wayne's son, Bruce Wayne, Jr. Even later, the grandson of Superman and Batman—Clark Wayne—develops a futuristic superhero identity: Knightwing.

All of these heroes and more—including the offspring of other members of the Justice League—continue to fight evil down through the generations, though there is one determined enemy that none of them seem capable of opposing: Time itself.

MORE POWERFUL THAN A LOCOMOTIVE

Yes, Barry dropped a "more powerful than a locomotive" reference at some point in his stories about Supergirl.

Just like in the introduction to the old radio and TV shows and cartoons about Superman.

MARS ATTACKS

The way the President was blasted into a green cloud felt very reminiscent of the disintegrations in Mars Attacks, the popular trading card property that has also been turned into comics, animation, and a live-action movie from Batman director Tim Burton over the years.

JULIE GREER

Iris's byline in the story about Crisis on Infinite Earths is now replaced by an entirely different reporter, no "Iris West" or "Iris West-Allen" at all.

This time around, it's Julie Greer, a reporter headquartered out of Keystone City in the comics.

In the comics, she was a reasonably ethical character who worked for a fairly unethical TV station, who intentionally blew comments made by the son of Wally West and Linda Park way out of proportion for ratings.

DOMINATOR DOTS

In the comics, the dots on the foreheads of Dominators were meant to indicate social caste.

That's not so in the TV version, where the Dominators have some kind of mind-control ability and, seemingly, the red dots also show up on the foreheads of those being mind-controlled.

"There was discussions about the size of their circles, and how that was indicative of where they stood in the caste system," The Flash and Supergirl showrunner Andrew Kreisberg said. "I'm sorry some of that stuff went away, just because it was great flavor, and I think the people who are fans of the original comic book would have seen a lot more of our joy at adapting 'Invasion!' in there, but to get these down to the proper time, that's the kind of stuff that tends to fall by the wayside."