The shadow of the upcoming "Crisis on Infinite Earths" looms over The Flash season 6, episode 2 - and this episode raises a lot of questions about just what's going on. This year's Arrowverse event is the biggest yet, and frankly ever single show appears to be building up towards it. A Crisis is coming, and both The Flash and Arrow are dealing with the potential death of their starring characters.

The Flash season 6 premiere ended with the Monitor revealing that the timeline has changed, and that Barry Allen is destined to die on December 10, 2019. This latest episode, "A Flash of the Lightning," sees Barry and Iris decide what to do about the Monitor's chilling warning. They come up with a smart solution; jump to the future, to the day after the Flash has died, in order to learn what's going on. Unfortunately this idea proves less than effective, and soon they're forced to approach Jay Garrick of Earth-3 for backup. Meanwhile, a sub-plot sees the rest of Team Flash deal with a dangerous new Meta, and uncover a mystery threat that may have been lurking in the background for years.

Related: The Flash Maps Out The Arrowverse's Entire Multiverse

The Flash season 6, episode 2 is actually quite impressive. Ironically, The Flash has often had pacing problems, and it would be very easy for season 6 to feel as though it was treading water ahead of "Crisis on Infinite Earths". But that isn't the case; the mystery of Ultraviolet really does feel ominous and intriguing, while Ramsay Rosso's experiments are headed in an unpredictable and fresh direction. Let's explore every unanswered question in The Flash season 6, episode 2.

10. How Did The Crisis On Infinite Earths Truly Begin?

The Flash Barry Allen Jay Garrick

The Flash season 6, episode 2 reveals that the Crisis is already happening - it's just consuming other Earths. Jay Garrick reveals to the Flash that he's been monitoring antimatter signatures across the Multiverse for the last year. He's even been able to run some sort of algorithm that tells him the entire Multiverse could be in danger. This is quite a significant revelation, because it confirms that cosmic forces have been in play for quite some time now. It suggests viewers should subtly reinterpret last year's "Elseworlds" event as the Monitor's initial response to a Multiversal catastrophe that was already happening.

9. Why Did The Timeline Change?

Cicada

Jay Garrick's news means the Crisis had begun to consume the Multiverse before the Flash's timeline changed. And yet, for some reason, in the initial timeline it wasn't due to hit Earth-1 until 2024; something changed in The Flash season 5 that affected the entire Multiverse, meaning the Crisis will be drawn to Earth-1 five years early. The change appears to be the destruction of Cicada's dagger, which was originally used to depower Metas. The clear implication is that, in the original timeline, Cicada's dagger was used to restrain someone who would otherwise have summoned the Crisis to Earth-1. With the dagger now gone, there's nothing to hold this mystery Meta in check any more, and the Crisis happens in 2019 instead.

8. Why Hasn't Flash Encountered This Antimatter Barrier Before?

The Flash Season 6 Episode 2 Helmet

The Arrowverse's time travel doesn't always make sense, but The Flash season 6, episode 2 nevertheless sees one of the smartest uses of this power to date. The Monitor has told Barry that he'll die on December 10, 2019, so the Flash decides to jump to December 11 to find out what's supposed to happen. Unfortunately, he encounters a mysterious antimatter barrier in the timestream, and barely escapes with his life. The curious question is just why this antimatter barrier exists now, when it wasn't there before. Why has Barry previously been able to run forward in time beyond the moment of his death? The only possible reason is that he's now too close to it. Ironically, that does mean there's probably a way to circumvent the antimatter barrier. Barry could simply travel back to the past, and then run forward to December 11, 2019, again.

Related: Arrow May Have Just Killed Off Two Key Flash Characters

7. Has Crisis On Infinite Earths Just Copied Doctor Strange's Infinity War Plot?

The Flash Doctor Strange

There are marked similarities between The Flash season 6, episode 2 and Doctor Strange's use of the Time Stone in Avengers: Infinity War. In this episode, Barry Allen's consciousness is projected forward through the timestream, and he experiences billions of possible futures - realizing that there is just one in which Iris and everybody he loves makes it out alive. This matches up perfectly with Doctor Strange's role in Avengers: Infinity War, where the Sorcerer Supreme explored over 14 million timelines and realized that there was only one in which the heroes won - and it required a sacrifice.

6. Are Barry And Iris Going To Tell Team Flash Everything?

Barry and Iris walk together

CW shows seem to thrive on secrets, and as a result it's no surprise that Barry and Iris initially decide not to clue the rest of their team in on Barry's fate and the Monitor's warning. By the end of The Flash season 6, episode 2, though, they're trying to decide whether it's time to spill the beans. It's a frankly welcome sign of maturity for Barry and Iris, and demonstrates that the showrunners have realized viewers are getting tired of ill-thought-through secrecy leading to drawn-out plots.

5. Who Are Allegra And Ultraviolet?

The Flash season 6, episode 2 introduces two brand new characters, both of whom possess the power to manipulate the electromagnetic spectrum. Allegra Garcia is loosely adapted from the comics, where she's the daughter of a supervillain called Wavelength and inherited his powers. Her cousin Esperanza is an entirely new character, who possesses an identical powerset. These feel like significant additions to the Arrowverse, not least because Allegra winds up getting a job with Iris.

4. Who Has Been Training Ultraviolet?

The Flash Ultraviolet close-up

Both Allegra and Ultraviolet gained their powers as a result of the particle accelerator explosion all the way back in The Flash season 1. Allegra didn't initially realize the offensive potential of her abilities, instead returning to a life of petty crime, but her cousin was left in a vegetative state. At some point, a mystery group acquired Ultraviolet, awoke her from her coma, and trained her as an assassin for hire. Right now, there's no information on who this group could be, or indeed on whether or not they've been training other Metas. This is a smart idea for The Flash, because it means Barry and his friends can wind up going against more experienced Metas who've mastered their skills, rather than usually dealing with people whose powers are out of control.

Related: The Flash Season 6 Cast & Character Guide

3. Is The Ultraviolet Plot Connected To Sue Dearborn's Disappearance?

The Flash Ralph Dibny Sue Dearbon

Superhero TV shows have a tendency of trying to draw all the threads together, and it's possible that Ultraviolet's training is somehow connected to another mystery disappearance. In the background, Ralph Dibny is investigating the missing Sue Dearborn. In the comics, Sue becomes Ralph's main love interest, and the two eventually marry. It could well be that Sue has been kidnapped by the same people who took Esperanza.

2. What Is The Flash's Top Speed?

The Flash Season 6

There's a strange line of dialogue in The Flash season 6, episode 2, with Gideon telling Flash that Ultraviolet light travels at 186,000 miles per second - 80 times Barry's top speed. The problem with this assertion, however, is that the last saw episode saw Barry Allen break out of a black hole. In order to do that, he'd have to travel faster than the speed of light - 186,282 miles per second.

1. What's Going On With The Ramsay Rosso Plot?

Meanwhile, in the background, Dr. Ramsay Rosso continues his experiments to conquer death. Over the course of The Flash season 6, episode 2, he conducts an illegal arms deal to acquire a weapon of some kind. When he's double-crossed, he lashes out with his new powers and kills the thug he was dealing with. A final stinger, however, suggests that the man has been resurrected as some sort of violent zombie. It's currently impossible to say quite where this plot is going.

More: It Took The Flash 6 Seasons For An (Almost) Comic Accurate Costume