The Supergirl Crossover: Will The CW Combine Supergirl Universe With Arrow And Flash, Or Will Girl Of Steel Only Visit The Other CW Superheroes?

The Supergirl crossover big event with The Girl of Steel will involve her visiting "Earth Prime" to help out the Flash, Green Arrow, and the Legends of Tomorrow with the scary alien invaders that are the big bad of the four night event. But apparently, the producers are actually not planning on using Flashpoint or a "Crisis on Infinite Earths" concept to fully combine Supergirl's world with theirs.

As reported by The Mary Sue, the producers of Supergirl– and all of the other DCTV Greg Berlanti shows on The CW – seem to have made the decision to keep Supergirl and her universe separate from the universe the other three-hit superhero shows reside in.

Crossovers Are Awesome

Some of the very best episodes of Arrow, The Flash, Legends of Tomorrow and – now – Supergirl have been ones where characters from one series have shown up on another show. There are several reasons why this particular storytelling technique is so effective for superhero shows like these.

For one thing, crossovers break up the current storyline of the shows involved, letting them do something a little different for a while. For example, if things have gotten a bit heavy and grim on Arrow– as they are wont to do – a quick crossover with The Flash can add a bit of humor and fun.

Crossovers also allow the writers to tell much bigger and more involved stories than they normally could. For instance, the four show crossover that The CW is planning for later this season will be – as Stephen Amell has pointed out – essentially a four-hour movie. Or at least, a miniseries.

The crossover also gives the producers and writers on these series a chance to introduce changes to their own shows in a way that they might not be able to otherwise. The recent Flashpoint incident on The Flash introduces unexpected changes to the other CW superhero series, such as the character of Digg now having a son rather than a daughter.

So Why Keep Them Separate?

As much fun as the crossovers are, the producers, actors, and writers all agree they are a major undertaking. Even with Supergirl now being filmed in Vancouver rather than Los Angeles, the logistics of any crossover between Supergirl and the other shows are daunting.

The principal problem is scheduling. All of the shows film their episodes more or less at the same time, making it difficult to work out a point in the story arcs for all four shows when they can get together for the big crossover event.

In fact, an example of how this could be a problem cropped up in last season's episode of Arrow. Early on in the season, we were teased with a future scene of Oliver Queen mourning at an unknown grave in a cemetery when the Flash – a.k.a. Barry Allen – streaks up to console him.

The problem was, when the episode containing this whole scene actually arrived, it was clear to viewers that the Flash – based on what was going on in his own show – no longer had his speed powers and could not have streaked up to the cemetery or anywhere else.

Greg Berlanti with Supergirl and the Flash.
Greg Berlanti with Supergirl and the Flash. [Image by The CW]

By having Supergirl remain in her own separate universe, crossovers between her and the Flash – the character she is most likely to interact with since she already has – will simplify at least some of the future crossovers. In other words, we won't be seeing Cat Grant or James Olson hang out with the green arrow anytime soon.

On the other hand, they could send the Martian Manhunter across the universal divide. As long as he stayed a CGI character, they wouldn't necessarily need David Harewood – the actor who plays him on Supergirl. But there would still be the concern about continuity mistakes.

What this all means is that the crossovers to the Supergirl universe are likely only to involve the Flash and maybe Cisco, while the Supergirl crossover to the other CW shows will probably only involve Supergirl herself coming over from her particular version of the Earth.

[Featured Image by The CW]