Warning: This article contains spoilers for The Flash season 5 episode 9.

The Flash's Elseworlds episode wasn't just any episode, it was the first part of the Arrowverse's annual crossover, which brought together three of the shared universe's shows (Legends of Tomorrow didn't take part in the Arrowverse crossover this year). "Elseworlds, Part 1" saw the CW heroes in a very different world from the one we know: one where our Barry Allen is actually the Green Arrow and Oliver Queen is the fastest man alive.

However, the only two people on Earth-1 aware of this change were Barry and Oliver themselves. This led to some pretty fun moments and revealing heart to hearts as Barry and Oliver struggled to find out what happened to their identities.

Related: Arrowverse: Elseworlds Crossover Schedule

The first episode of the three-night event also introduced both Dr. John Deegan and the Monitor. The scene showed the Monitor presenting Deegan with a mysterious book that seemed to provide some kind of knowledge and the ability to alter reality. It appeared that the Monitor could even see when Cisco used his powers to show Oliver and Barry his vibe. To get back to reality these heroes have a big challenge ahead of them. With an episode of this size comes lots of questions. Here are the biggest ones after "Elseworlds, Part 1".

6. How Did the Body Swap Happen In the First Place?

Elseworlds Oliver Queen and Barry Allen

The biggest question in The Flash's Elseworlds episode is just how Barry and Oliver swapped bodies in the first place. The two of them come to the realization at different points: Oliver waking up in Barry's bed and Barry training with Diggle. Barry and Oliver have retained all their memories and are the only ones who know anything is different. At first Team Flash doesn't believe Barry and Oliver and have them locked in the Pipeline. However, with Iris' heart telling her the truth and Cisco ready to believe anything is possible they eventually come around.

But what caused it to happen in the first place? As of this episode, we don't know enough yet about the Monitor and his powers. The characters know something took place, but they don't know what caused it. They don't even know how to help Oliver and Barry switch back. Throughout the episode Cisco kept remaking about the red skies, could the weather be playing a role or is just part of the ominous things to come?

5. Why Did the Body Swap Only Happen on Earth-1?

Oliver, Barry, and Kara talk to Cisco in Elseworlds Part 1

To get help with their conundrum, Barry and Oliver head to Kara on Earth-38. She instantly recognizes them. So why is Earth-1 the only one affected by the Monitor's plan? Does he has a specific reason for targeting this Earth? As the Elseworlds trailer has shown, the Monitor has been traveling the multiverse causing destruction wherever he goes. He has already attacked the world of 1990's Flash on Earth-90 and now he seems set to ruin yet another world. Is he just set on total domination or causing more chaos by rewriting reality?

4. Where is Nora?

The Flash 5.2 Nora West-Allen

Crossovers are a fun way to get all the Arrowverse casts together sharing a screen. However, this episode had one glaring omission: Nora West-Allen. It's not unusual for characters to sit out crossover; after all, each show has a number of characters and the scheduling going into the episodes makes giving every character a role impossible. But it seems very strange that they didn't even mention Nora's absence or explain it in anyway.

Related: The Flash's Batman Beyond Easter Egg Spoiled Nora Twist Weeks Ago

Wouldn't Barry want to know his daughter was okay after he wakes up realizing his entire world has changed? Was Nora rewritten out of existence? Of course, it's possible Nora was in the future with Thawne, but again, why wouldn't anyone at least wonder about her whereabouts? Will she show up in the crossovers at all? Given how The Flash season 5 midseason finale ended, it seems likely that the producers will want to avoid continuing the Nora storyline until The Flash season 5 returns in 2019.

Page 2 of 2: Amazo, Black Suit Superman, & More Flash Elseworlds Questions

Elseworlds Amazo

3. Where Did AMAZO Come From?

With the ability to duplicate the heroes' powers, AMAZO was a pretty fun villain to feature in the crossover. But where did this robot come from? Does its further Arrowverse connection mean anything? In Arrow season 2, flashbacks introduced Professor Ivo, a man obsessed with finding the secret to the Japanese serum known as mirakuru, and in this episode of The Flash, Cisco and Caitlin discover that the AMAZO runs on a synthetic form of the same drug. They also show that the robot was built at Ivo Labs. However, Ivo died back in Arrow season 2 on Lian Yu. Was the robot a fun way to tie in past seasons of the Arrowverse shows or is their more to this connection? It's possible that Ivo left the research for his company to finish what he couldn't do, but that's something that the Elseworlds crossover will have to answer at some point.

2. How Does Superman Turn Bad?

Elseworlds Tyler Hoechlin as Superman Black Suit

From the promos (and Elseworlds set photos) we know that a black-suited Superman is in the future of Elseworlds. In this episode, though, he acted quite the opposite, donning his classic suit and fighting Amazo alongside his cousin and her friends. So what will cause Superman's switch? Is it part of the reality rewriting? It's possible that Superman himself could come from another Earth, seeing as there are characters from several different timelines uniting in the fight against the Monitor. This episode of The Flash left out a lot of what we know is coming including Batwoman and John Wesley Shipp as the Flash yet. Just how Clark turns against the others is sure to be an important part of the crossover, especially for Kara, who will be forced to fight against him family member once more. With someone as powerful as Superman on his side, Deegan is proving to be a strong threat.

1. What Does the Monitor Want & How Does Dr. John Deegan Fit In?

Jeremy Davies as Dr. John Deegan Elseworlds Part 1

The Monitor was the one who gave Deegan the seemingly magical book he is using to rewrite reality. Why did the Monitor hand over the book? Could he not use it himself? Does he have an even bigger plan that involves Deegan too? And what do they both want? Motivations of the villains of Arrowverse episodes are not always the clearest, but someone going through this much trouble clearly has an agenda. The Monitor appears to be extremely powerful, as evident by him crushing cars without touching them, not to mention seeing into Cisco's vibes. His power combined with Deegan's hatred, as well as the desire to use powers from metahumans, is a dangerous combination. Going forward, hopefully, their motivations become more clear as well as a way to defeat them.

More: When The Flash Returns in 2019 (& What to Expect)

 Elseworlds continues with Arrow on Monday at 8 PM and ends with Supergirl on Tuesday at 8 PM on the CW.