After two middling middle chapters, Crisis on Earth-X goes out with a bang. There's a bit of everything thrown into this concluding episode, likely because everyone involved both in front and behind the camera saw the end and wanted to go for broke. It's not entirely unexpected, but on top of two extended, sometimes-chaotic, overly-filled-with-CGI action sequences, the writers manage to squeeze in an admittedly emotional subplot that continues the consequences of the very end of Part Three.

And yes, the emotion surrounding the death of Professor Martin Stein is dented by the fact that Victor Garber has wanted out of Legends of Tomorrow for a while now, everything around the subplot works on an emotional level. I didn't expect this kind of pathos to be present in a shared universe where death is treated like an inconvenient hiccup, but that only makes the scenes shown here all that more impressive. The connection between Martin and Jax has been a running thread not only in the background of the past three parts of Crisis on Earth-X, but also a running subplot through the current season of Legends of Tomorrow.

So the stakes between the two of them are much more heightened than say, the marital issues of Oliver and Felicity, or the sister bonding between Kara and Alex Danvers. I certainly believe that Martin considers Jax the son he never had, and that Jax has always regarded Martin as a father figure to replace his absent biological father, and that connection makes their inevitable separation all that more painful and heartbreaking. Not only that, but Martin had significant interactions with the characters in The Flash so his death affects them as well as the Legends. They were Martin's surrogate family, on top of the growing family that he wanted to get back to.

Speaking of the Legends, they do factor into the action sequences that fill out the rest of the episode. They enter STAR Labs at the most inopportune time, right as Thawne is about to cut out Kara's heart. They thwart that, as well as participate in taking out Metallo-X in a flashy and spectacular manner. Like the various missions of the Legends, the battle sequences are filled with CGI, though the production staff has learned how to harness everything so that the sequences don't look as fake or cheap as it could have been if they tried something like this crossover just a couple of years ago.

The STAR Labs battle is an appetizer for the full-on battle sequence that occurs over Central City. The crossover event really commits to the comic book aesthetic, putting out various action and group shots that look like they've leapt straight from the comic book page onto the small screen. The Right Stuff-esque shot as the heroes walk in a straight line towards a bunch of Nazis is an even better improvement on the smaller shot from Part Two. The episode maintains this epic sort of feel to everything throughout the course of the battle. We get to see all sorts of cool sequences, from Supergirl and Overgirl duking it out in the skies above Central City, to Killer Frost transporting Zari and Amaya on an ice slide towards the Nazi Waverider, and Oliver battling Dark Oliver as Kara carries an exploding Overgirl towards the atmosphere and away from danger. Because Crisis on Earth-X committed to making Dark Oliver and Overgirl a romantic couple, the pain Dark Oliver feels over his wife's death is palpable, even if that lasts just for a moment before Oliver shoots him dead. He did promise earlier to kill his dark doppleganger, so the episode pays off what was hinted in chapters before.

It all ends in an all-too-neat manner, though that's not a criticism of this huge crossover event. It had to end that way so that the writers could advance the arc that started all of this: Barry and Iris finally get married by Dig, who's been absent for the entire "crisis." Not only that, but Felicity decides to change her entire stance on not getting married to Oliver, something that's also been a running thread through the previous three parts of the crossover, and make it a surprise double wedding! I consider myself very tolerant of the Oliver-Felicity romance so I didn't mind this unexpected development, but I wouldn't be surprised if those fans who hate the relationship would hate it. The crossover comes full circle, and gets an altogether entertaining sendoff.