There have been important developments on all four of The CW's DC superhero TV shows during their respective ongoing seasons. Oliver Queen (Stephen Amell) and the current 'Team Arrow' are dealing with the mysterious threat that is Prometheus (among other killers in Star City) on Arrow; Kara Danvers/Zor-El (Melissa Benoist) has more than enough alien-related problems on her plate to deal with on Supergirl; Barry Allen (Grant Gustin) and his friends/family are still reeling from the effects of the Flashpoint alternate timeline on The Flash; and the Legends are slowly beginning to realize that they're on a collision course with the Legion of Doom on Legends of Tomorrow.
These plot threads will, to a certain degree, overlap with one another during the fast-approaching 'Invasion!': a four-night crossover event on The CW that begins on Supergirl and concludes with Legends. 'Invasion' is based on the DC comic book narrative of the same name and sees Earth in the Arrow/Flash/Legends universe attacked by an alien race known as the Dominators - prompting Barry to take another trip through the multi-verse to Supergirl's version of Earth and bring Kara back with him, to join in the fight.
The CW has released a handful of previews for the 'Invasion!' event already, including a found-footage style promo teasing the Dominators themselves. Most of the trailers and TV spots for 'Invasion' have focused more on teasing the interactions between various characters during the event and the trend continues with the latest trailer (see above), helpfully titled 'Heroes v Aliens'.
Said 'Heroes v Aliens' trailer focuses in particular on an exchange between Kara and Mick Rory/Heat Wave (Dominic Purcell) during the 'Invasion!' event, suggesting that (not so surprisingly) the duo won't automatically become BFFs the way that Barry and Kara did during their own first encounter - and that Kara and Mick probably won't be singing songs together anytime soon, either.
Most of the 'Invasion!' crossover's entertainment value is expected to come from these interactions between The CW's superheroes (like that between Kara and Mick). The event should have some larger impact on the ongoing storylines in the Arrowverse too, especially in the case of Arrow (which will see its 100th episode air as part of the event). 'Invasion' may still amount to more of a fun one-off adventure for the Arrowverse than a pivotal step forward in its development - but considering that this is the first multi-TV series crossover of its kind, that could be enough for fans for now and may yet lead to bigger DCTV-related developments, down the line.
[vn_gallery name="Arrowverse Invasion! Crossover Posters" id="845674"]
The DC TV crossover kicks off with Supergirl ‘Medusa’ Monday November 28 at 8pm on The CW, continuing with The Flash ‘Invasion!’ in the same timeslot on Tuesday November 29, Arrow ‘Invasion!’ on Wednesday November 30, and concludes with Legends of Tomorrow ‘Invasion!’ on Thursday December 1.
Source: The CW