[Warning: The following contains spoilers for the Arrow Season 7 finale. Read at your own risk!]

The yearly Arrowverse crossover event has become a staple of The CW, but this year is going to be a particularly epic one since it will be the last to incorporate Arrow, the flagship show of the franchise.

Arrow's final season will include the 2019 crossover, "Crisis on Infinite Earths," and though it's still very early days, we have a few teases about what's to come thanks to the hints and spoilers dropped here and there in Arrow, Supergirl, and The Flash, as well as in last year's "Elseworlds" crossover. Here is everything we know so far about the epic TV event.

It will likely air this fall. The Arrowverse crossover event has historically aired in the fall, usually in late November or early December. If The CW keeps to that schedule, we'll likely see "Crisis on Infinite Earths" before the year is out.

Oliver Queen (Stephen Amell) will die to save the multi-verse. In the Arrow Season 7 finale, we finally discovered the price of the deal Oliver made with the Monitor (LaMonica Garrett) in "Elseworlds." He told Oliver that the crisis would claim his life, and in Arrow's flash-forwards, we saw Oliver's headstone with his death dated in 2019.

It could potentially serve as the Arrow series finale. Beyond the fact that Oliver will apparently die in the crisis, we know Arrow's final season will only consist of 10 episodes, meaning it probably won't continue into 2020. That leaves us with the possibility that Arrow's series finale will actually serve as the crossover finale as well, effectively putting an end to Oliver Queen's story.

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We'll learn about Barry's (Grant Gustin) mysterious disappearance in the future. In The Flash pilot, a headline from the future revealed the Flash vanishes in a "crisis," but we don't know much beyond that. Executive producer Todd Helbing revealed we may finally get some answers about Barry's disappearance in "Crisis on Infinite Earths."

"We've certainly been teasing [the headline] a long time, but it's a major factor in next year's crossover," Helbing said.

This seemed to be confirmed again with The Flash's Season 5 finale, which saw the future headline change its date from 2024 down to 2019 in the final bonus scene.

The Flash

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DC's Legends of Tomorrowwill probably take part. Though the show sat last year's crossover out, don't count on the Legends sitting on the bench for this crossover event. CW President Mark Pedowitz explained at the Television Critics Association winter press tour that he's hopeful Legends will get to participate this time around.

"The only reason Legends wasn't [in it] this year was the complications in production of doing these things. We don't want to wear out everybody before the season ends. But we're talking about a number of different ways to go. It is 'Crisis on Infinite Earths' and if you know the history, things collapse," Pedowitz said.

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