The moment Supergirl was announced for CBS, Flash and Arrow fans have hoped for a potential crossover between The CW and CBS. Recent responses from executive producers Andrew Kreisberg and Greg Berlanti have overwhelmingly dashed our hopes, but it looks like Supergirl pulled a fast one. Barry Allen is coming to National City!

The CW confirmed that Grant Gustin will appear as his Flash-y alter-ego on the March 28 outing of Supergirl, though details are being kept under wraps for now. Presumably, Barry will hop universes into Kara’s world, rather than vice-versa, so as to not give continuity too much of a headache.

Say the producers:

We are so incredibly excited to announce something that we have dreamed of happening since we starting making Supergirl —The Flash and Supergirl are teaming up! We want to thank Grant Gustin for making the time to come visit (on top of his already immense workload) and all of the folks at CBS, The CW, Warner Bros., and DC for working this out. And finally thanks to the fans and journalists who have kept asking for this to happen. It is our pleasure and hope to create an episode worthy of everyone’s enthusiasm and support.

Earlier in January, Berlanti had offered:

I would love it, a lot of things would have to go right and people would have to say ‘Yes.’ It would have to figured out very soon. It would all have to be figured out in the next month or so. As it remains right now we’ve talked internally about how cool it would be, but we haven’t had official conversations. [The CW chief Mark Pedowitz] is supportive.

Prior to that, Kreisberg even questioned the legality of any such crossover, including among the looser Legends of Tomorrow. Plenty more details will shake out in the coming weeks, but what should we expect when The Flash and Supergirl meet?

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