Ever since the epic four-way crossover was announced back in May, we’ve been waiting patiently to see Supergirl (Melissa Benoist), Team Flash, Team Arrow, and Team Legends team up to take down the powerful threat, the Dominators. Well, the long-awaited event is almost here and everyday, we’re learning more and more about what we should expect to see. On Wednesday, the synopses for all four episodes were released and just yesterday, The CW released the photo galleries and first official sneak peek for the crossover, appropriately titled ‘Heroes Vs. Aliens’.

The event kicks off with Supergirl on Monday, November 28th, when Barry (Grant Gustin) and Cisco (Carlos Valdes) cross the multiverse to recruit the Girl of Steel herself. Before that happens, though, Kara has more personal matters to deal with. Mon-El (Chris Wood) is unconscious…again (presumably due to his visit to Cadmus next week) and Mama Danvers (Helen Slater) arrives to try and help.

On the episode of The Flash immediately following, Barry introduces Kara to his fellow Earth-1 heroes and they all team up for the very first time to invade what looks like the Dominators’ base of operations. In another scene, Barry and Oliver (Stephen Amell) look like they might be in over their heads taking on the aliens all by themselves.

'The Flash' Unveils New Logo for Season 4

Wednesday’s episode of Arrow is where things take a turn for the freaky. Supergirl and Team Flash look to be nowhere in sight but we do get some incredible looks at the alternate reality Oliver finds himself waking up in–one where he never got on the Queen’s Gambit. Hence the return of his parents, Robert (Jamey Sheridan) and Moira Queen (Susanna Thompson), and his soon-to-be-wife, Laurel Lance (Katie Cassidy). Lauriver fans aren’t the only ones who are going to love this episode, though. It seems as if Raylicity becomes (and stays) a thing in Ollie’s dream world.

'Arrow' Actor Auditions for Lead Role in DCEU's 'Shazam!'

Finally, on Legends of Tomorrow, we return to the normal timeline where our heroes team up one last time to defeat the invading alien race.

Photo Gallery & Extended Trailer for 'The Flash' Season 4 Premiere

You still with us? Good! Because here’s the moment we’ve all been dying to see: Barry introducing Kara to Team Arrow and Team Legends…and Diggle’s (David Ramsey) subsequent reaction to the last daughter of Krypton. (Also, a moment I personally geeked out about: Kara calling Cisco’s powers “cool”.)

Arrowverse Crossover: "Crisis on Earth X"

And that’s it…for now at least. There’s still one episode of Supergirl and one episode of The Flash next week before the festivities begin but we’ll be sure to keep you updated on all things ‘Invasion!’. Stay tuned!