The CW's five-episode "Crisis on Infinite Earths" crossover is a mere three weeks away, bringing together the heroes of Arrowverse, and beyond, to face off against their biggest threat yet, the Anti-Monitor. After the worlds of the multiverse were tested by the Monitor last year in "Elseworlds," his brother, the Anti-Monitor, now seeks to destroy them.

A handful of series-specific teasers for "Crisis" were released late last week, dropping tantalizing clues about the fates of the characters -- and Earths -- as the antimatter wave sweeps across the multiverse. Let's break them down.

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The Cosmic Treadmill - and An Emblem Amid the Rubble

In DC's epic 1985-1986 crossover Crisis on Infinite Earths, by Marv Wolfman and George Perez, Barry Allen sacrifices himself while stopping the Anti-Monitor from using his antimatter cannon to destroy five Earths. It appears a similar tragedy is being set up in the Arrowverse crossover, as we're shown a glimpse of The Flash (Grant Gustin) running on his cosmic treadmill, a classic time-travel device from the comics that was introduced in Season 1.

Later, The Flash's logo chest emblem lays amid the rubble in what could be the destroyed treadmill. Showrunner Eric Wallace confirmed Barry will die in "Crisis." The question remains how that death will be undone, as, unlike Arrow, The Flash isn't ending just yet.

Farewell to Black Lightning's Earth?

In the Black Lightning teaser, Team Flash tries to recruit Jefferson Pierce (Cress Williams), now off his own Earth, into the fight. Pierce responds, "You just told me my world is over, and you need my help?"

That suggests Black Lightning's Earth might have fallen at the hands of the Anti-Monitor and the antimatter wave. It's been confirmed that characters from the Black Lightning universe will be in the event. If their Earth is destroyed, it certainly opens up the possibility they will join the Arrowverse continuity.

Cisco Is Vibe Again?

In The Flash's Season 5 finaleCisco Ramon (Carlos Valdes) injected himself with a metahuman cure to get rid of his Vibe powers. So, it's pretty surprising to see a fully costumed Vibe in the background of the Black Lightning teaser. The suit appears to be identical to the one he previously wore on The Flash.

However, considering the premise of "Crisis," it simply could be a Vibe from another Earth. Regardless of which Cisco it turns out to be, his dimensional-breach powers could work well in clutch to bring in characters from other universes to make a stand against the Anti-Monitor.

The Death of Superman

For better or worse, DC's 1992-1993 crossover storyline "The Death of Superman" was a major moment for superhero comics. Killing off the character brought mainstream media attention back to comics, and Superman #75 remains one of the bestselling comics of all time. While the publisher eventually resurrected the Man of Steel, the striking image of his tattered cape flying like a flag is one of the most iconic in the character's history.

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In the Supergirl teaser, the tattered red cape appears amid the aftermath of destruction. The imagery could very well be a reference to Brandon Routh's Kingdom Come Superman dying in the crisis. Earth-Two's Superman does die in the Infinite Crisis crossover. It would be surprising to see the Kingdom Come version of the character making any more appearances beyond the event - although, stranger things have happened.

What Happens to the Atom?

Routh will leave Legends of Tomorrow during its upcoming fifth season, which kicks off in January. That could hold major implications for the character's fate in "Crisis." In the Legends teaser, the Atom is glimpsed grabbing his leg while walking slowly; he appears to be injured. With Routh's imminent departure, it would make sense that Ray Palmer may not make it out of the "Crisis" alive. However, that's pure speculation.

His loss during the crossover would give the character a heroic send-off, but it would also allow the new version of the Atom, Ryan Choi (Osric Chau), to assume the mantle ahead of the Season 5 premiere.

It seems clear "Crisis on Infinite Earths" will substantially alter the Arrowverse, as heroes and Earths fall.

"Crisis on Infinite Earths" begins Sunday, Dec. 8, at 8 p.m. ET/PT on Supergirl, then continues in Batwoman on Monday, Dec. 9, at 8 p.m. ET/PT and on The Flash on Tuesday, Dec. 10, at 8 p.m. ET/PT. After the winter hiatus, the crossover will conclude on Tuesday, Jan. 14, on Arrow at 8 p.m. ET/PT and on DC's Legends of Tomorrow at 9 p.m. ET/PT.

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