Middle chapters of a large story are always difficult to review. There's no true starting point, and there's no end either. The impression is not complete because the story is not complete. That's very much true of this episode of Arrow. What I do find interesting to see here is the different styles at work, and clashing together in one episode.

Part One of Crisis on Earth-X wasn't an episode of Supergirl so much as an episode of The Flash with the characters of Supergirl and Alex Danvers making extended cameos. The feeling doesn't really extend here, as the characters of Arrow are more involved with the ongoing storyline. I can't be sure what was going on with the coordination between four different shows with four different ongoing plotlines was like during production of the crossover, but I wonder if the writers and production staff of Arrow perhaps took a look at Supergirl, and decided they didn't want to do what they did. Part One of Crisis on Earth-X was purely setup, and it's then Arrow's job (as well as The Flash and Legends of Tomorrow) to carry the baton to the finish line.  So Part Two immediately declares itself a full-fledged Arrow episode by revealing that the captured Prometheus in the STAR Labs Pipeline is not Adrian Chase, but rather Tommy Merlyn! He's alive after five years! Only, he's not really Tommy. At least, he's not the Tommy that Oliver and Felicity knew way back when.

We find out more and more about what life is like on Earth-X, something that was in very short supply in Part One. It's a hard and horrific place (which Harry undersold), one where the Nazis, by virtue of their developing the atomic bomb before the Americans do, win World War II, and literally take over the entire world. Supers like Prometheus and Dark Arrow and Overgirl and the Reverse Flash are in the upper echelon of the current Reich, and they've hatched an ambitious plan to try and take over Earth-1. This is wading more into the overall plot of Crisis on Earth-X, which involves the mirror supervillains trying to acquire some sort of mysterious prism that holds the key to the "Earth-Xers" taking over Earth-1.

The key difference between Part One and Part Two here, is that this episode takes some time out to check in on where every character is mentally. Felicity (loudly) blurted out in Barry and Iris' rehearsal dinner that she "didn't want to marry (Oliver)," and so both characters are left to deal with the aftermath of that statement. Their discussion after Dark Tommy committed suicide (which somehow mentally affects this Oliver) is smart, and understated, even though it's very emotionally charged. The Oliver of Arrow's sixth season is in a much more mature mental space than he was in earlier seasons, and he knows what he wants. But so does Felicity, and it boils down to sticking to her perspective, which is one that is afraid of taking the next step in their relationship.

That fear is rooted in legitimate concerns, as the last time they got engaged, Felicity got shot and couldn't walk for a time. Apparently, the Flashpoint timeline created by Barry didn't affect that event in both of their lives. The problem with this exploration of the hated Olicity relationship is that the writers don't know where to go with the relationship's status. All of that intimate talk between the two of them results in both of them being in the same place at the end. Both Felicity and Oliver discuss their feelings and mentality with others, apart from each other, but those discussions don't really bear much fruit, either.

So then, what's left? The action, much like the wedding action sequence at the end of Part One, at least still works. Also like Part One, the cheap television special effects sometimes bog down the proceedings. Arrow made filming action and stunt fight sequences their bread and butter throughout five seasons' time, and there are a couple of fights that play to that same spirit (a fight in a dark-lit warehouse is filmed in one take inside and back from four people simultaneously), but it does sometimes get stale. It's funny for both Oliver and Kara to get thrown by the fact that Dark Arrow and Overgirl are married to each other, something that I suspected from the very beginning of this episode, but never really had such an impression during Part One. And the Dark Arrow's plan to split up the fighting forces between STAR Labs and the portal to Earth-X is nicely structured to get to the next part of the crossover.

But it's not a natural endpoint to the story. It's yet another cliffhanger, although this one was better than Part One. Felicity and Iris (plus an unconscious Cisco) are trapped at STAR Labs with Dark Arrow, while everyone else, including some of the members of Team Arrow, are now stuck in Earth-X. Presumably, the majority of Part Three, nominally The Flash's turn for Crisis on Earth-X, will take place in Earth-X, and that means we'll get to learn even more about the world and its characters. But like Supergirl before it, I think these crossover episodes are shortchanging the characters we've spent years getting to know all about. That doesn't really sit well with me, even as I've been enjoying much of the crossover event.