Spoilers ahead for the Invasion! crossover airing on The CW, including tonight's episode of DC's Legends of Tomorrow.
In 1988, aliens invaded the DC Universe. 28 years later, they took on the DC heroes of The CW in an unprecedented four-series live-action crossover, which concludes tonight.
In the comics, a race called The Dominators -- who had been active antagonists in the Legion of Super-Heroes comics set in the 30th Century -- rallied a group of powerful, mostly-malevolent alien races together to launch an assault on Earth. Their reasoning? Earth's fast-growing metahuman population took a world that had historically not been a player in interplanetary politics and transformed it into a legitimate threat.
That motivation -- the Dominators have come to Earth to stem the tide of the superhuman threat -- is one that holds in the TV event. They're here becuase they're concerned that "the scourge of your planet will become the scourge of ours," as we heard in trailers, and that scourge is metahumans.
So -- what else does the TV version have in common with the comics?
Both a lot and not very much. In the broad strokes, it was a very similar story, but in specific details it diverged pretty much all the time.
In the comics, as noted, it was an army of various different alien races, with different sorts of ships and different approaches to combat. They attacked with overwhelming force, took over a continent (Australia, the populated land mass with the lowest instance of metahuman activity), killed millions (per the Daily Planet that came out around that time), and set up bases around the world, including undersea and in easy-to-defend locales like Australia and Cuba.
In the comics, as on TV, The Dominators fail to properly gauge the potential threats to their invasion force and ultimately end up turning tail abruptly. On TV, it's becuase the heroes manage to cobble together a plan that will make the price of staying higher than the cost of leaving. In the comics, it was -- ironically, perhaps, considering what a big role Mon-El is playing on Supergirl right now -- the involvement of a group of Daxamites that turned the tide.
There was a larger, thematic thing that the Invasion! crossovers have in common, and one that seems to have been largely missed in a lot of the discussion of the TV version up to this point.
Mainstream superhero comic were, of course, birthed with the first appearance of Superman in 1938, so by 1988, DC was celebrating its 50th anniversary.
(No, we're not going with the Arrow 100th anniversary aspect, although that's a kind of neat coincidence.)
However, the 1986 continuity reboot following the events of Crisis on Infinite Earths meant that the newly-realigned DC Universe had never faced a large-scale alien invasion. Yes, they were somewhat old-hat for readers -- and certain characters had certainly interacted with aliens before, including Hawkman and Hawkwoman, whose race (the Thanagarians) were a part of the invasion force.
But for most of the heroes of the DC Universe, and nearly all of the human population of the DCU who were being victimized by aggressive aliens? This was the first time the had solid confirmation that there even were aliens, let alone an attack from same. The world, it seemed, was getting continually stranger and stranger, as Superman gave birth to a generation of superheroes and supervillains, followed by aliens looking to exploit those metahumans.
In a very real way, the DC Universe was never quite the same again following Invasion!, as the idea of the metagene was introduced to the public at large (that's something we already pretty much had in place at this point in the shows), and the confirmation of intelligent alien life confirmed for the first time.
(Aside from Superman, there were fairly few high-profile aliens, and most of them were "last survivors," so there was a sense that aliens were not an imminent threat for the most part.)
NEXT: The Flash, Arrow, Supergirl, Legends of Tomorrow Crossover Trailer / First Look At The Dominators / Todd McFarlane On Designing Invasion!'s Dominators / Will Joe West Die During The Invasion! Crossover? / Enter To Win An Ultra-Rare Invasion! Crossover T-Shirt
Supergirl airs Monday nights at 8 p.m. on The CW. New episodes return in January. The midseason finales for The Flash, Arrow, and DC's Legends of Tomorrow will air next week on Tuesday, Wednesday, and Thursday, respectively at 8 p.m. ET/PT.