Legends Of Tomorrow Teases Invasion Crossover With Found Footage

We're less than a week away from the beginning of the CW's epic "Invasion!" crossover, but a new teaser hints that it might actually have begun a long, long time ago.

The clip (above) comes courtesy of Legends of Tomorrow, and it's in the style of "found footage" from a military archive. While it initially looks to be a conventional battle scene (seemingly set during World War II), it's soon revealed that the human soldiers are actually battling aliens from a massive spaceship looming overhead.

Just before the film ends, we get a good look at one of the aliens–likely one of the Dominators who will wreak enough havoc to cause a four-episode team-up across Legends of Tomorrow, Supergirl, Arrow, and The Flash.

Does this mean the Legends will be taking all the heroes back in time? Or is it just meant to tell us that the Dominators have attacked Earth before? We'll find out when the crossover begins with Supergirl on Nov. 28, followed by The Flash on Nov. 29, Arrow on Nov. 30, and concludes with Legends of Tomorrow on Dec. 1.

For a more official look at what to expect, watch the teaser for the Supergirl episode.