Crisis on Infinite Earths(Spoilers)

Final trailer for the 2 hour climax this Tuesday

And with that, the Crisis is over, and a lot of things are different. The two hour finale began with a flashback to the Monitor's origin. They merged his origin with that of Krona, the proto-Guardian of the Universe who was determined to view the dawn of time, including making Mar Novu a native of Maltus. He travels to the dawn of time and accidentally screws up, opening a breach to the Anti-Matter universe, where he encounters his doppelganger, the Anti-Monitor.

Cut to a few months after Part 3, where the Paragons(Kara, J'onn, Sara, Kate, Ryan, and Lex) are trying to survive. Barry had vanished at some point, though he returns in spectacular fashion, having failed to enter the Speed Force and inadvertently jumping forward the intervening months. He tries to make another attempt when Oliver appears, now the Spectre. He informs the Paragons about Novu's actions in the past. Splitting up, Kara, Ryan, and Lex travel to Maltus to try to convince the young Novu to not go through with his time travel experiment. Meanwhile, Sara, Barry, Oliver, J'onn, and Kate head back to the dawn of time. Along the way, the Anti-Monitor attacks and they're flung loose, spread out across the Speed Force at various points. Barry realizes it, and sets out to find the others. We're treated to revisits to various points in Arrow's history(the aftermath of Sara's death, the confrontation between Oliver and Ray Palmer, the terse conversation between Kara and Oliver during the Dominator invasion, and the aftermath of the fight against Deegan in Elseworlds). Along the way, Barry finds out the deal that Oliver had made with the Monitor during Elseworlds, in that he had traded his own life to save Kara and Barry. We're also treated to an amusing surprise cameo by the DCEU's Flash, as played by Ezra Miller.

The Paragons reunited in the dawn of time(the nature of the multiverse making Kara, Ryan, and Lex's mission moot), they fight the shadow demons while Oliver takes on the Anti-Monitor one on one. We get the expected, "you have failed this universe" from Oliver as he lights the spark to create the universe, the Paragons focusing on their aspects(Kara/Hope, Sara/Destiny, Kate/Courage, Barry/Love, J'onn/Honor, Ryan/Humanity, and Lex/Truth) to fan the flames of creation. The Anti-Monitor is destroyed and Oliver dies(again), Barry and Sara at his side. Then we get a fade to white as the universe is reborn.

Kara wakes up in her apartment, hoping that what had happened was a dream. She gets a call from Nia, reminding her that she was supposed to cover a ceremony. She gets there, learning that it's a ceremony presenting Lex Luthor with a Peace Prize. He throws her a smug wink That's right, Lex is now regarded as a great man, he and Lena apparently being Kara and Superman's greatest advocates. On top of that, the DEO is effectively a Luthorcorp subsidiary. J'onn shows up, explaining to Kara that he and the other Paragons are the only ones who remember what happened. There's an emergency and Kara goes off to fight the Weather Witch, a recent addition to the Flash's rogues. Barry shows up, and they're both confused by what's going on. They're approached by an older man(as played by comics legend and Crisis author Marv Wolfman), asking for their autographs. Through this they realize that more has changed than they think.

Sara finds herself in Star City, also remembering what had happened. She meets up with Ray Palmer, who's clueless until J'onn arrives and gives him a quick mental download of everything that had happened. J'onn proceeds to do that to Team Arrow as well, who confirms that Oliver is MIA. Nash Wells is found in the underground tunnel where he had accidentally released the Anti-Monitor. J'onn jogs Nash and Caitlin's memory, everyone understandably angry at Nash given that he was responsible for all this pain.

Once again, there's another alert, in the form of a giant Beebo(don't ask), rampaging through Star City. Kara, Sara, Barry, Ray, Mick, and Kate fight it before realizing it's a diversion, distracting the heroes from a wannabe "sorcerer" knocking over a bank. He's quickly dispatched, and all is well.

Or not.

It appears that the Anti-Monitor survived and is still out to destroy the universe. While the rest of the heroes face off against him, Ray, Ryan, and Nash work on a bomb/MacGuffin that would cause the Anti-Monitor to perpetually shrink into infinity. After a long fight, the bomb is complete, Kara chucking it into the Anti-Monitor's chest. It's finally over.

We get a montage as the President of the United States eulogizes Oliver. Along the way, we learn that Lois and Clark have two sons in this new Earth-Prime(as opposed to just the one at the start of the crossover) and that Sara Diggle, John Diggle's daughter who had been erased and replaced by a son years ago due to Flashpoint once again exists alongside John Jr. Kara, Sara, J'onn, Kate, Clark, Jefferson Pierce, and Barry hold a memorial for Oliver at the STAR Labs hanger that looks a lot like the Hall of Justice, saying their goodbyes to their fallen friend. Barry then unveils a round table, with seats bearing everyone's insignia, including an arrowhead, symbolically remaining vacant. So begins the proto-Justice League.

All told, it was actually a pretty good crossover. It wasn't perfect by any means, but it had a lot of good moments, and nearly everyone got their share of the spotlight. Word is they will hold off on massive crossovers from here on out, which makes sense. It'll be hard to top this one.

You forgot about one more mythology gag at the end: The weird monkey laugh(which I initially thought could be The Joker having somehow stumbled onto the sorta!Hall of justice) and a shot of an open cage marked "Gleek" similar to how Gorilla Grodd was foreshadowed way back at the start of The Flash season 1. Could the apparent existence of Gleek mean that the next crossover event will include the Wonder Twins?

To think, this is how it all began.