The CW Network released an extended trailer for Legends of Tomorrow Season 2, debuting Thursday, October 13, which offers our first brief glimpse at the network's highly-anticipated four-part crossover event. We learn in this trailer that the Legends are contacted in the Waverider by none other than Barry Allen in the year 2056, who apologizes for reaching out, stating he can't "risk putting anymore lives in danger." We then get to see Arrow, the present-day Flash, Supergirl and the Legends uniting on a rooftop.

While we don't see them in this extended trailer, courtesy of The CW Network, it was recently confirmed that this crossover will air in late fall, most likely in early December, with the villains being a group of DC Comics characters known as The Dominators. These villains are a sinister, technologically advanced alien race who view Earth's tendency to generate super-powered people as a sign that humans may essentially evolve to be genetically superior, leading to their decision to wipe out humanity. The Dominators' story was part of a three-issue comic crossover event titled 'Invasion', which was drawn by Spawn creator Todd McFarlane.

While the crossover is certainly something many fans are looking forward to this season, this trailer makes it clear that there is a lot more happening than just this crossover. At the end of Season 1, fans got their first look at Rex Tyler aka Hourman (played by Patrick J. Adams - Suits) who issued a dire warning. It was to be their first encounter with a member of the Justice Society of America, and we get a closer look at the JSA in this new trailer.

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The Legends of Tomorrow producers also announced at Comic-Con that the Legends will be facing off against TV's first-ever team of Super-Villains: the Legion of Doom, who fans will recognize as Malcolm Merlyn (John Barrowman), Damien Darhk (Neal McDonough), the Reverse-Flash (Matt Letscher) and Captain Cold (Wentworth Miller), all of whom are shown in this trailer. Both Wentworth Miller and John Barrowman signed new deals with The CW this summer, allowing their characters to appear across multiple shows, and Neal McDonough's Damien Darhk character will now have a recurring role on DC's Legends of Tomorrow.

We also reported this summer that Sarah Grey has come aboard to play Stargirl, with Maisie Richardson-Sellers has come aboard as the new Vixen, while Matthew MacCaull is playing Commander Steel. Along with this new trailer, we also have full photo galleries from the first two episodes of DC's Legends of Tomorrow Season 2, Out of Time, airing Thursday, October 13 and The Justice Society of America, airing on Thursday, October 20 on The CW. Take a look at this extended trailer and the new photo galleries below.

Out of Time photo 1
Out of Time photo 2
Out of Time photo 3
Out of Time photo 4
Out of Time photo 5
Out of Time photo 6
The Justice Society of America photo 1
The Justice Society of America photo 2
The Justice Society of America photo 3
The Justice Society of America photo 4
The Justice Society of America photo 5
The Justice Society of America photo 6