The Crisis on Infinite Earths trailer provide quite a few teases of what to expect from the story of the upcoming Arrowverse crossover. The five-part event, which begins December 8, is right around the corner. The first three parts (Batwoman, Supergirl, and The Flash), will air across three nights, while the final two parts (Arrow and Legends of Tomorrow) will air together on January 14 to conclude the crossover.

Based on the 1985-1986 comic book miniseries of the same name, Crisis on Infinite Earths is the Arrowverse’s sixth annual crossover event. First teased at the end of last year’s Elseworlds, Crisis on Infinite Earths presents the heroes of the Arrowverse with its biggest threat yet. It’s been known since the Arrow season 7 finale that an event called the Crisis may bring about the end of the multiverse itself. Heroes from all five shows - along with a few heroes from outside the Arrowverse - will have to band together if they have any hope of preventing the destruction of the multiverse.

The Flash and Arrow have been building up to the Crisis all season long with ominous warnings from the Monitor (LaMonica Garrett). So far, the main characters don’t have much knowledge about what will happen in the Crisis, apart from the Monitor’s prediction that Oliver Queen (Stephen Amell) and Barry Allen (Grant Gustin) will have to give their lives to save the multiverse. As for what to expect from the story of the crossover, its large cast and list of notable guest stars does give a few clues about the plot and its connections to the comics. Also, the Crisis on Infinite Earths trailers reveal interesting details about the story.

Harbinger Recruits Heroes For The Crisis

The short teasers for Crisis on Infinite Earths confirm that Arrow’s Lyla Michaels (Audrey Marie Anderson) will be the character who warns some of the Arrowverse heroes that the Crisis has started. The teasers show Lyla, suited up as the Harbinger, separately contacting Barry, Batwoman (Ruby Rose), and the Legends, and informing them that the multiverse is about to end.

Lyla’s role in the Crisis is currently being set up in Arrow season 8. It was recently revealed that while Oliver was running errands for the Monitor, Lyla was moonlighting for him as well. Her secret was exposed when Earth-2’s Laurel Lance (Katie Cassidy) outed her to Oliver and Diggle (David Ramsey). Lyla will serve the Monitor in an even greater capacity during the Crisis, since she’s set to become the Arrowverse’s Harbinger, a character from DC Comics who the Monitor tasks with recruiting heroes to stop the Crisis. It would appear that Lyla will follow in the footsteps of her comic book counterpart.

Cisco Becomes Vibe Again

Cisco (Carlos Valdez) can be spotted back in costume as Vibe. It’s only natural that the heroes will need all hands on deck for dealing with the Crisis, but Cisco becoming Vibe means that something must happen either on The Flash or during the Crisis that will allow this to take place. Cisco, who wanted to live a more normal life, gave himself the metahuman cure in The Flash season 5 finale. Cisco, now powerless, has gone back to just being Team Flash’s tech expert and one of its two lead scientists. How he gets his powers back is unclear, but with a cosmic being like the Monitor on their side, it doesn’t seem impossible at all. If Monitor is capable of resurrecting people, giving Cisco his powers back seems like a simple task. Cisco’s Vibe powers, which allow him to open up portals to other Earths, could be instrumental in combating the Crisis and traveling across multiple Earths.

The Death of Superman

Superman’s tattered cape is seen blowing in the wind. This is an obvious homage to the cover of 1993’s Superman #75, which was part of the crossover story, “Death of Superman”, in which the Man of Steel was killed by Doomsday. The cape could mean that one of the crossover’s three Supermen will die in the Crisis. Tyler Hoechlin’s Superman is coming back for his own show, and Smallville’s Clark Kent (Tom Welling) may have only filmed one scene, so both could be safe. Instead, the cape could signify the death of Brandon Routh’s Kingdom Come Superman. Another possibility is that a fourth Superman, whose face we may never see, could have died off-screen. This could explain why the cape is more comic book accurate than the ones worn by the Supermen in Crisis on Infinite Earths.

Black Lightning’s Earth May Be Destroyed

The Crisis will finally incorporate Black Lightning into the Arrowverse by bringing its hero, Jefferson Pierce (Cress Williams) to the crossover. The trailer shows him reacting to the Crisis in anger and making a comment about his world ending. If so, this could mean that everyone that Black Lightning cares about will be killed in the event. Even if this does happen, it seems unlikely to stick, since Black Lighting is so far removed from the Arrowverse. Regardless, the Crisis suggests that big changes may be in store for Black Lightning.

The Flash Runs On His Cosmic Treadmill

One of the Crisis on Infinite Earths promos opens with Barry running on his cosmic treadmill from DC Comics, a device which Barry could use to reach the speed necessary for time travel. It was also present in the comic book version of Crisis on Infinite Earths. How it will be implemented in the TV crossover remains to be seen, but it could be used for inter-dimensional travel, or perhaps as a way of increasing Barry’s speed. Either way, it may play a role in Barry’s arc in Crisis. As the comics indicate, Barry’s speed will be needed for beating the Anti-Monitor. In the comics, Barry had to run faster than ever to destroy the Anti-Monitor’s antimatter cannon. Barry’s actions cost him his life, but gave the heroes a fighting chance.

More: Arrowverse Characters Who Died In The Crisis On Infinite Earths Comics