[Minor spoilers ahead] So the big crossover episode of Supergirl aired on Monday, while we await word of renewal. Did The Flash give it a good enough boost? Time will tell, as there has been no announcement yet, but it definitely had an effect on the ratings. Overall viewers were up 21% and the all-important 18-49 demo was up 31% over last week, to see how the DC television universe would handle this network-and-multiverse-crossing episode. It also had the highest rating for any scripted show that night.
So, how did they handle the crossover, given that Flash’s Earth seems to have no awareness of Kara or her better known cousin or other aliens, while Kara’s version has no metahumans? Simple – the comic multiverse, DC-style.
The Flash has already established the multi-Earth concept, with the Golden Age Flash, Jay Garrick, coming to Barry Allen’s Earth-One, and Barry going to Jay’s Earth-Two. So to expand a bit, Barry does something (to be explained in The Flash‘s Tuesday episode) back home that results in him arriving on Kara’s version of Earth, where he helps out and then Kara gives him a boost – literally – to get back. This now opened up a myriad of possibilities in storytelling with other DC characters, in such a way that they can be independent of shows or even the movies – we already know that a movie version of Barry Allen’s Flash will be played by Ezra Miller instead of Grant Gustin. So it sets op independent franchises that in some ways can lean on each other occasionally.
It also provides a gimmick that can unfortunately be used as an end-around to any intractable situation, so let’s hope they keep this trick in the back pocket unless it actually helps with the story.