The CW's marketing machine has been working overtime to promote the TV crossover event known as 'Invasion!' and/or 'Heroes v Aliens', in the week leading up to the event's premiere. DCTV shows Supergirl, The Flash, Arrow and Legends of Tomorrow will all cross over during the course of 'Heroes v Aliens', starting with the next episode of Supergirl season 2, titled 'Medusa'.
'Medusa' will mostly function as a continuation of the main plot threads on Supergirl this season (Kara battling Project Cadmus, the origins of Guardian, Alex Danvers coming out). A clip has been released, teasing how The Flash's Barry Allen and Cisco Ramon - somewhat literally - intrude on the developments in 'Medusa' in order to bring Kara over to their corner of the Arrow/Flash multiverse that Supergirl is a part of (as was established during the season 1 crossover episode, 'Worlds Finest'). The reason? Arrow/The Flash's Earth is under attack by the Dominators (the aliens from the 1980s Invasion! DC Comics story that 'Heroes v Aliens' is based on) and they need Kara's help to fight back.
The new 'Heroes v Aliens' extended trailer released online by The CW (watch it above) highlights footage from the first encounter between Supergirl and the various Arrow, Legends of Tomorrow and The Flash characters who have never seen the Kryptonian warrior in action before. Most of the rest of the trailer focuses on clips from the battle that ensues between Earth's defenders and their extraterrestrial opponents, but there are some brief moments of levity here and there. Felicity Smoak and HR Wells (aka. Harrison Wells from Earth-19) seem happy about the superhero team-up, if nothing else.
Arrow's episode during 'Heroes v Aliens' is also the show's 100th episode overall. Said episode will thus fittingly allow Stephen Amell's Oliver Queen (and the series itself, in a meta-narrative sense) to reflect on what's come before, as he finds himself living in an alternate reality where he never boarded the Queen’s Gambit, all those years ago. This won't be permanent, of course, but it should allow the Arrow portion of this crossover to be the most character development heavy one too, whereas The Flash and Legends of Tomorrow's episodes ought to be more plot-driven by comparison.
Everything in the Arrowverse will go back to business as usual after 'Heroes v Aliens' is done, as the four DCTV shows will thereafter be preparing to take their midseason break over the winter holidays. Things will be a bit different when the series return in 2017 though, what with Legends of Tomorrow moving to join The Flash on Tuesday nights. It's not clear what (if any) impact that move could have on another (potential) four-way crossover event next year, but we do know The Flash and Supergirl will be teaming up again in 2017 - and this time, with a whole lot more singing involved.
'Invasion!'/'Heroes v Aliens' begins Monday, Nov. 28 with Supergirl at 8 p.m. EST on The CW, and continues with The Flash at the same time on Tuesday, Arrow on Wednesday, and Legends of Tomorrow on Thursday.
Source: The CW