Tonight, Arrow -- which has spent much of season 5 returning to its roots as a "grounded, gritty crime drama" -- will see its hero deal with an alternate reality during a fight against aliens co-starring a dozen or so superheroes.
That's something that has frozen a handful of the show's die-hard fans in their tracks, with series star Stephen Amell being quizzed at a recent convention about why the show's hundredth episode would play so against-type.
Of course, that's not an entirely fair characterization. The "alternate reality" that Oliver will inhabit will be one largely without powered people, and will play on season 1 storytelling ideas, Oliver's own feelings of loss and regret, and other largely human and universal themes.
But now that the pandora's box of extraterrestrial life has been opened, will Arrow, The Flash, and DC's Legends of Tomorrow start to see them all over the place, like Supergirl does?
The answer is, probably not.
"I think that what's so nice about the shows for us, is that each of the shows has their own identity, especially this season," executive producer Andrew Kreisberg, who works on all four DC/CW series, told reporters at a screening of the Invasion! event on Monday. "It feels like every show has sort of doubled down on what it's about. With Arrow, we've really returned more to the sort of gritty crime drama that it originally was. There's so many echos in this season to the earlier seasons. The Flash has the metahumans and Legends of Tomorrow has time travel and Supergirl doubled down on the alien aspect. I think that's what makes the shows feel different so that you're not watching four hours of the same stuff every week. You're really getting a different flavor and a different world. Whereas, now that possibility's opened, that because they have all faced aliens, there's certainly no plans to have an ongoing or bring up an alien storyline on Arrow. That really feels like the purview of Supergirl."
That's not entirely unlike the role of magic in Arrow; it played a big role last year, but has been barely-present this season. Damieh Darhk, last year's big bad, has been popping up in Legends of Tomorrow, along with numerous other notable monsters from the CW TV past. And, of course, there's the matter of a Thanagarian attack that was teased in season 1 -- so don't be too surprised if any potential future alien involvement outside of Supergirl heads there (though that's speculation, and not what the producers said).
Arrow, The Flash, and Supergirl will cross over with DC's Legends of Tomorrow this week in "Invasion!" a three-part crossover that starts in the final moments of an episode of Supergirl and then plays through the other series. Based on the 1988 comic book event miniseries Invasion! from Keith Giffen, Bill Mantlo, Todd McFarlane, Bart Sears, and the crossover -- with its marketing title "Heroes vs. Aliens" -- will closely track the plot of that storyline: aliens will be assembled by The Dominators and descend on Earth to bring an end to the "threat" of Earth's burgeoning metahuman community.
In the comics, the Dominion were secretly hoping to build their own super-race, and as a result created a handful of new superheroes in the course of the story.
In the TV version, rather than assembling a loose alliance of dangerous alien races, the Dominators will apparently be mind-controlling the aliens that join them. That's a revelation that suggests even the heroes might be forced to take one another (or at least the alien Supergirl) on at some point in the story.
NEXT: The Flash, Arrow, Supergirl, Legends of Tomorrow Crossover Trailer / First Look At The Dominators / Invasion! Crossover Promo Photos / Potential The Flash Spoiler Spotted On Set / Will Joe West Die During The Invasion! Crossover? / Enter To Win An Ultra-Rare Invasion! Crossover T-Shirt
Supergirl airs Mondays at 8 p.m. ET/PT; The Flash on Tuesdays at the same time; Arrowon Wednesdays and DC's Legends of Tomorrow on Thursdays. All four series air on The CW. The "Invasion!" crossover will air beginning November 28.