Soon enough, the team has figured out what’s really going on with the Earth-Xers: The Ray and Mr. Terrific deduce that Overgirl’s radiation may soon turn her into a supernova that’ll destroy the planet, and that she’s vanished because they’re aboard a Nazi Waverider. Oliver figures that they’ll use Overgirl to threaten Earth-1 and force them to surrender — and he’s right.
Evil Arrow offers to leave their Earth alone if they turn over Supergirl and her heart, but Oliver refuses, saying that his Team Arrow, the Legends, The Flash, and everyone working with them won’t ever abandon their friends, and Ray adds that while they can’t bring Stein back, they can protect his home from Nazis.
And so, the team lands in Central City, ready to face down Evil Arrow and his Nazis. We finally get the crossover slow-mo shot we’ve been waiting for, of all the heroes in a line, facing down the masked baddies. The fighting breaks out, and as usual, we get some neat smaller moments in all the chaos: Leo tells Mick they can’t just roast people (“Haven’t you heard of due process?” he questions Mick, who obviously doesn’t care); Sara and Alex fight side-by-side again; and Mr. Terrific tosses the Atom for a fun combo.
But the battle boils down to a few fronts in the end: First, Felicity, Iris, Harry, and Cisco help Killer Frost Frozone her way on board the Nazi Waverider with Amaya and Zari to disable the shields. The Flash takes on Reverse-Flash, but in the end, Barry lets Eobard go once again, knowing that he’ll just come back again and again to torture him. (After all, Eobard promises him that he’ll be back, perhaps wearing a new face.) Supergirl lures Overgirl off the ship, and the pair take to the skies, but when Overgirl’s radiation jumps off the charts and she starts to go supernova, Kara’s forced to fly her above the Earth so Overgirl can explode. When Overgirl self-destructs, Evil Arrow falls to his knees, giving Oliver time to kill him once and for all.
And then Supergirl falls out of the sky, caught just in time by Nate, who makes a “man of steel” pun because of course he does.
The rest of the hour is devoted to an epilogue of sorts as everyone returns to their respective homes. Almost, anyway: Leo opts to stick around Earth-1 for a little longer, kissing The Ray goodbye as he departs for home. (Which is really too bad; it’s always good to see Russell Tovey around on the small screen.) Stein’s funeral takes place, and Jax delivers a heartfelt speech before sharing a hug with Clarissa, Lily, and baby Ronnie. Mick cries, too, while Leo encourages him to let it all out. And lastly, each of Stein’s closest super friends thank him as they say goodbye: Sara thanks him for believing in her, Caitlin asks him to say hi to Ronnie, and Barry thanks him for bringing him home. (Aaaand I think I have something in my eye again.)
Still, that’s not the end of the crossover. Sara retreats with her Legends, saying goodbye to Alex before she takes off, hugging as they tell each other to trust their instincts, and that they’ll find someone someday. Kara and Alex then go back to their Earth, thanking Oliver and Barry for hosting them.
Left alone, Barry and Iris look at each other and decide that, well, they might as well get married right then and there. And so, Barry picks up the ordained Diggle from the Team Arrow lair, and after Diggle finishes vomiting, he gets ready to marry Barry and Iris. They say their (very, very, there’s-something-in-my-eye-again sweet) vows, but before they seal the deal, Felicity interrupts.
After hearing Barry and Iris’ vows, she’s come around to the idea of being married to Oliver after all. Despite the danger and all their ups and downs, she wants to be married to him, and so Diggle gets to marry two super-couples, ending the episode on a high note of love and super-friendship.
It’s cute, and lovely, and certainly a nice way to wrap up a somewhat bloated crossover event. But still: Stein, guys, Stein. I repeat: NooooOOOOOOOoooooooooOOOOOOOOoooooooooooooooooooo. Please join me in revisiting this clip of Stein distracting everyone in Mission Control with the power of SONG.