With the Arrowverse poised to adapt the classic comic book mini-series Crisis on Infinite Earths in 2019, it seems likely that both Green Arrow and Superman will be making the ultimate heroic sacrifice as part of the annual crossover event. While hints had been dropped before about the famous storyline someday being brought to life in live-action, fans were stunned that the timetable had apparently been bumped up following the recent Elseworlds event, which hinted as some big changes to come in the Arrowverse. They also hinted at the probable deaths of The Man of Steel and The Emerald Archer.

Perhaps the most ambitious and involved fictional universe ever produced for television, the Arrowverse is a shared reality formed from many of the superhero shows airing on The CW Network. These include Arrow, The Flash and Supergirl. Since 2014, it has been an annual event each fall for the Arrowverse shows to cross-over, as part of a big shared storyline. The 2018 crossover event, Elseworlds, ended with a title card proclaiming that the next event would be called Crisis on Infinite Earths and that it would air in Fall 2019.

Related: Arrowverse Elseworlds Crossover Synopses Reveal New Story Details

The Elseworlds crossover this year helped lay the groundwork for Crisis on Infinite Earths (in addition to some already established set-up). Of course, a Crisis on Infinite Earths is famous in the comics for a number of things, including some significant character deaths. While it was Flash and Supergirl in the comics, there's reason to believe Oliver Queen and Clark Kent will be among the fallen once the battle to save all reality is concluded on television. What does this mean for the future of the Arrowverse?

Elseworlds Explained

Arrowverse Elseworlds Batwoman

Elseworlds opened with Oliver Queen (Green Arrow) and Barry Allen (The Flash) waking up one morning to find they had seemingly swapped lives. Though they still had their own faces and memories, they possessed one another's skills and powers and everyone - even their own wives - saw Oliver as Barry and vice versa. Theorizing that since nobody on Earth seemed to realize something was wrong except them, Barry and Oliver traveled to another Earth in search of confirmation that they weren't going crazy. This led them to Earth-38- the setting of Supergirl and home of Kara Danvers (Supergirl).

Once Kara confirmed that she could see Barry and Oliver for who they really were, the trio returned to Earth-1 in search of answers. The trail led them to Gotham City and a psychiatrist at Arkham Asylum named John Deegan, who had been given The Book of Destiny - a cosmic artifact capable of rewriting reality. Their attempt to confront Deegan resulted in him facilitating a jailbreak to cover his escape and led to an encounter with Batwoman - the new protector of Gotham City following Batman's disappearance years earlier. This spurred Deegan to use the Book of Destiny to rewrite reality again, making himself into the Superman of Earth-1. He also transformed every hero on Earth-1 into a villain and imprisoned Supergirl, who the book would not alter directly as she was not part of its universe.

Barry and Oliver (now a duo of non-powered bank robbers called The Trigger Twins) retained their memories thanks to the intervention of The Monitor - the cosmic being who gave Deegan the Book of Destiny. The Monitor revealed that he had empowered Deegan as part of a test of Earth-1's heroes, as he had tested the guardians of other Earths in search of beings who could stand up against a great evil that threatened to destroy all of reality in the near future. Armed with this knowledge, Barry and Oliver were able to return to Earth-38 and recruit the Superman of Kara's world to fight Deegan in earnest.

Related: Elseworlds: Every Easter Egg & Reference In The Arrowverse Crossover

The heroes were able to recover the Book of Destiny long enough to restore themselves to normal before Deegan stole it back. Superman, who had been the one to use the book, revealed he had forseen the deaths of The Flash and Supergirl and they matched the circumstances described in the plan The Flash came up with to stop Deegan. Undeterred, The Flash and Supergirl went off to face their apparent deaths, as Green Arrow confronted The Monitor and read him the riot act regarding the immorality of his actions, killing good people as part of some engineered test.

The Monitor was apparently pleased, as his tests were meant to gauge the heroes' morality - not their competence. He said that the destinies of The Flash and Supergirl might be rewritten, but said some kind of price would have to be paid to maintain the balance. Green Arrow apparently agreed to pay the price, as The Flash's plan worked and he and Supergirl both survived the final battle with Deegan. Elseworlds concluded with reality restored, a shriveled and comatose Deegan incarcerated in Arkham Asylum and a man in a gold mask declaring that "Worlds will live. Worlds will die. And nothing will ever be the same again, " just before a title card appeared, which said that Crisis on Infinite Earths would come in Fall 2019.

Page 2: Why Crisis Could Kill Superman and Green Arrow

Worlds shatter in Crisis on Infinite Earths comics.

What Is Crisis On Infinite Earths?

Crisis on Infinite Earths was a 12-issue mini-series released by DC Comics in 1985 to coincide with their 50th anniversary, giving all the characters they had created in that time a grand send-off. This proved necessary because the reality of DC Comics had become a hodgepodge of multiple universes over the years, as DC Comics bought up other properties and turned every newly acquired comic book line into an alternate Earth. This made things difficult for new readers in the pre-Internet days, as there was no way to easily look up why Superman's cousin in some stories was a teenage girl called Supergirl and in others she was a young woman called Power Girl or why Shazam never teamed up with the Justice League.

This confusion led writer Marv Wolfman (best known today as co-creator of the most popular incarnation of the Teen Titans) to propose a way to combine all of DC Comics' realities into a single shared universe. Wolfman created The Monitor - a cosmic being who was seen aiding the villains of various realities. It was ultimately revealed that The Monitor was a cosmic manifestation of all the material universes and that his opposite number, the Anti-Monitor, had begun destroying other realities so that only his anti-matter universe would exist. Testing the heroes of the various positive-matter universes through their villains, The Monitor began building an army that would be capable of facing the Anti-Monitor. Thus began the greatest battle in cosmic history, as the heroes and villains of multiple Earths joined forces to save all that existed.

Related: 15 Confusing DC Comics Storylines Explained

How The Flash and Supergirl Died In The Comics' Crisis

Split images of Barry Allen dying and Superman lifting Supergirl's body in Crisis on Infinite Earths

While many characters died during Crisis on Infinite Earths, the deaths of Barry Allen (The Flash of Earth-One) and Kara Zor-El (Supergirl of Earth-One) were easily the most notable. Supergirl died in Crisis on Infinite Earths #7, after being beaten to death in a one-on-one battle with the Anti-Monitor himself. Kara's sacrifice saved the life of her cousin, Superman, and destroyed the machinery the Anti-Monitor was using to forcibly merge several Earths, inflicting cataclysmic damage upon them all.

Barry Allen would meet his final fate one issue later in Crisis on Infinite Earths #8. Imprisoned in the anti-matter universe, The Flash found a way to break free and discovered that The Anti-Monitor had begun constructing a great anti-matter canon that would be capable of destroying multiple positive-matter universes with a single shot. Running faster than he had ever run before, The Flash was able to destroy the cannon by generating a vibrational frequency that weakened its unstable core, turning the energy contained within the doomsday device upon itself. Barry Allen seemingly died then, his physical form disintegrating and leaving behind only his costume.

Why Green Arrow And Superman Will Die In The TV Crisis

Stephen Amell as Green Arrow and Tyler Hoechlin as Superman

The Flash television series has hinted at Barry's eventual heroic sacrifice since its first episode, with a newspaper from 2024 proclaiming that The Flash disappeared after some manner of Crisis. This was reaffirmed in the most recent season, with a newspaper from 2049 and The Flash's daughter from the future confirming that The Flash never returned home. However, recent events on The Flash have shown that the timeline is malleable and the proclamation that Crisis on Infinite Earths is coming five years ahead of when it was anticipated indicates that something big has changed on a cosmic level.

All of this puts The CW in a bit of a quandary. The Flash is easily the network's most popular show and Supergirl is similarly popular with their core demographic, if not quite as highly rated. It makes little sense, from the network's perspective, to sacrifice two of their most popular series purely for the sake of emulating a classic comic book storyline. The shows' writers would probably also prefer not to precisely retell a story to which everyone already knows the ending.

Related: Flash Theory: Barry Disappears Early Thanks To Nora

Elseworlds suggested an out, however, with the idea that Barry and Kara had been fated to die in an earlier battle once reality had been rewritten by John Deegan. We know that Oliver Queen has paid some kind of price to save his friends, thinking they will be needed to save the Earth in the coming Crisis, though the exact cost has yet to be revealed. It is worth noting, however, that nothing has been said about Oliver Queen being alive in the future of Star City 2038 during Arrow's season 7 flash-forwards. It's also worth noting that Green Arrow has sacrificed himself to save others in several comic book storylines, including Grant Morrison's Final Crisis and his original death in the Green Arrow storyline 'Where Angels Fear To Tread'.

Clearly Oliver Queen is being set up for some manner of heroic sacrifice, but what of Superman? Elseworlds concluded with Superman effectively retiring so he could focus on being a father to the baby that he and Lois Lane were having together. Despite him feeling that Kara is more than capable of replacing him as Earth-38's chief protector, it seems highly unlikely that Clark would sit on the sidelines with all of reality at stake during Crisis on Infinite Earths. It seems likely then that he and Kara will trade roles with their comic-book counterparts and that Clark will sacrifice himself to save Kara from The Anti-Monitor.

The Future of The Arrowverse, Post-Crisis

Arrow Season 7 New Green Arrow

Assuming that this plays out as predicted, there will be some major changes to the Arrowverse. Presumably the Arrowverse would emulate DC Comics immediately after Crisis on Infinite Earths and the wounded alternate realities would merge into a single, solid universe. This would leave Supergirl set on the same Earth as the other Arrowverse shows and make future team-ups a good deal easier to facilitate.

While it is possible that other versions of Oliver Queen and Clark Kent might be reborn into this new universe as in the comics, it seems unlikely the show-runners would cheapen their sacrifice in this manner. Arrow might continue, for instance, with Emikio Queen taking up her half-brother's bow and identity. On the other hand, there have been rumors that The CW might be interested in reviving Lois And Clark with Tyler Hoechlin and Elizabeth Tulloch after seeing their interactions as Clark Kent and Lois Lane in Elseworlds. Whatever happens, 2019 is bound to bring big things to the Arrowverse.

More: How The Arrowverse Has Already Set Up Crisis On Infinite Earths