Note: This article contains spoilers from the Elseworlds crossover event.

Elseworlds, The CW’s 2018 Arrowverse crossover, aired this week, creating some major “what if” scenarios for Green Arrow, the Flash, and Supergirl. When the three-night event wrapped on Tuesday, December 11, it left a few loose ends and teased the 2019 crossover – Crisis on Infinite Earths.

Elseworlds saw Dr. John Deegan given the power to rewrite reality, which he does by causing Barry and Oliver to switch powers and lives. They go to Kara’s Earth to seek her help righting the situation, which takes them to Gotham where they meet Batwoman and Deegan. When the Monitor chides Deegan for not thinking bigger, the doctor uses the book to make himself into Superman, puts Kara in the Pipeline at STAR Labs, and turns Barry and Oliver into the Trigger Twins.

As Kara and Barry race around the world trying to stop the destruction, Oliver contacts the Monitor and strikes a deal to save their lives – the terms of which were not shared during the episode. In the end, Deegan is turned into Dr. Destiny and as he’s being confined to Arkham Asylum, he instantly becomes friends with Psycho-Pirate. The masked villain comforts Dr. Destiny by saying, “worlds will live, worlds will die, and nothing will ever be the same.” Which is the tagline for the Crisis on Infinite Earths limited series, published in 1985-1986.

Crisis houses a larger threat than the Monitor – the Anti-Monitor, who can destroy realities with antimatter to become the sole ruler of all realities. Given that power, it already seems like the 2019 Arrowverse crossover will be pretty epic.

The closing minute of Elseworlds with the Crisis teaser can be seen below.