The big day is finally here! As Iris and Barry’s wedding approaches, the heroes of two worlds converge to wish their friends the best.

And they are not alone…

This is very much an episode of two halves and both are great. The first is a breezy comedy that focuses on the run up to the wedding and gives the Flash supporting cast some really nice moments. Barry and Iris, despite Barry’s two season long parade of terrible life choices, have turned into two of the Arrowverse’s designated adults and this episode does a really good job of celebrating that. Season 1 Iris would have thrown a multi-episode tantrum over what happens here. Season 2 Barry would have gone back in time, tried to change it and probably inadvertently erased all dogs from time. Nowadays, thankfully, they’re smart, grounded, sensible and nice people it’s easy to root for. And they’re not alone either, with Jesse L Martin on typically great form. Joe’s open, deeply emotional tribute to his family is a highlight of the episode.

It’s not alone either. The episode’s best material is given to Melissa Benoist, Chyler Leigh and Caity Lotz. Benoist and Leigh neatly balance the comedic elements of Kara and Alex’s currently slightly rubbish lives with the real emotional hits they’ve both taken. Leigh and Lotz have an instant, easy chemistry and make a tremendously fun couple. But it’s Kara’s honest, totally sincere joy that her sister has put herself out there that really lands the episode. The foundation of love and respect the Danvers sisters have for one another could be cloying but instead it’s sweet, genuine and inspiring. Not to mention funny without being mean spirited.

Then the second half hits and the episode turns the volume all the way up. The fight with the Nazis gives pretty much everyone a moment in the spotlight. Mick’s joyously casual attitude towards pyrotechnics, Alex and Sara taking down Prometheus as a team, Killer Frost slicing through Nazis and Wally literally pulling bullets from the air and throwing them back into the guns are all highlights. Better still, each one of the individual fights is designed to teach you about these people’s characters. The heroes are all fighting defensively, the occasional villains could care less and the Nazis want to kill everyone. Action as character driving character’s actions.

Verdict: The end result, not to mention the predictable if still fun end reveal, feels epic and, crucially, earned. There’s no sense of this story being stretched or padded out to fill four episodes. Instead, this feels like act one in something major and is a hell of a way to start this year’s crossover. 9/10

Alasdair Stuart