The team travel to Gotham to chase down a lead, meet its protector, discover what happened to its other protector and just how much trouble they’re in.

This may be the most impressively designed, from a narrative point of view, crossover the CW shows have done to date. Here’s what happens in this instalment:

We get answers about the Monitor and an overt reference to a Crisis

Kate Kane, Batwoman and Gotham are introduced. As is the very good reason no one’s gone there on the shows in seven years.

The issues with Oliver and Felicity are largely resolved.

There’s a very large Arkham breakout.

Barry and Oliver gain a greater understanding of who the other one is.

Continuity references galore. My favourite was the Bane mask from Dark Knight Rises.

Let’s work through them in order. That first one may actually be the most impressive. It not only makes the Monitor more of a threat but ties the Flash’s future history to all three shows and in doing so actually makes this a bigger and more interesting threat. The Monitor is trying to help, just in the worst possible way, which also gives him a welcome, alien spin.

Kate Kane steals the show. Ruby Rose isn’t given a tremendous amount to do in the suit but has a good chunk of screen time as Kate and she’s perfect. Whether it’s her charming fatalism, her crumpled idealism or the very clear flirting between her and Kara, this is Kate exactly as she should be. The Batwoman scenes impress too and it’s interesting that her fighting style has been differentiated from Oliver’s so clearly so early. Oliver will hit you ten times precisely to dismantle you. Kate will hit you once to drop you. Plus she uses height, technology, speed and intimidation brilliantly. In other words she’s written like she would have to be; a smaller human acutely aware of how little time she has to win any given fight and trained to a level where she will anyway. Plus the premise for the Batwoman show with Bruce missing and Gotham a warzone is brilliant. I really hope it’s greenlit.

The episode doesn’t skimp on action either. Diggle versus an entire Arkham wing is great as is the Barry/Ollie/Surprise cameos fight that follows it. Even better, that ties into the theme of the crossover: the two men gaining a greater understanding of the other. That in turn leads to a genuinely lovely moment between Oliver and Felicity and some fantastic gags as they struggle to adapt to being the other.

Verdict: Massive in scope, intimate in focus and ambitious in execution this is great. My one quibble would be how little Superman and Lois we’ve got so far but that’s it. Otherwise this is great and I can’t wait to see how it ends. 9/10

Alasdair Stuart