Earlier this year, The CW showed off an epic teaser trailer for DC's Legends of Tomorrow. But, as it turns out, none of that footage is going to be included in the series itself. One of the most interesting items on display was the return of Sara Lance as The White Canary. While it seemed that she would be getting her origin story told in DC's Legends of Tomorrow, producer Marc Guggenheim confirms that her backstory will be set up in Arrow Season 4.

Caity Lotz's Black Canary was killed off in Arrow Season 3, and her return has been a hot topic of conversation amongst fans. The trailer confirmed that Sara is being brought back from the dead through the Lazarus Pit. While it seemed that her superhero origin would be told in full as part of DC's Legends of Tomorrow, fans will learn how Lance became White Canary in the first few episodes of Arrow Season 4. Marc Guggenheim explained the follow.

"The White Canary will be launched in the first few episodes of Arrow. 4x08, our typical crossover episode, will be doing a lot of heavy-lifting in terms of getting the Legends of Tomorrow characters set up and also seeing where they are with relation to The Flash. It's a big episode."

So, this means that Arrow Season 4's eighth episode will be one giant crossover with both The Flash and DC's Legends of Tomorrow, setting each show on its respective course in relation to the other. As we saw in the teaser trailer for DC's Legends of Tomorrow, Barry Allen and Oliver Queen play an important role in the new superhero team's existence. And it appears that this small screen Justice League will be a fully working operation by the time DC's Legends of Tomorrow premieres in spring 2016.

There have already been several characters confirmed for DC's Legends of Tomorrow, including Arrow's Atom (Brandon Routh) and the White Canary (Caity Lotz), The Flash's Captain Cold (Wentworth Miller), Heat Wave (Dominic Purcell), and Dr. Martin Stein Victor Garber (Victor Garber), along with new characters such as Rip Hunter (Arthur Darvill) and Hawkgirl (Ciara Renee). Though not part of the initial team line-up, Hawkman will also be making multiple appearances in the first season, though the character has yet to be cast.

Marc Guggenheim is comparing DC's Legends of Tomorrow to the heist film Ocean's Eleven. The synopsis reads: When heroes alone are not enough...The world needs legends. Having seen the future, one he will desperately try to prevent from happening, time-traveling rogue Rip Hunter is tasked with assembling a disparate group of both heroes and villains to confront an unstoppable threat - one in which not only is the planet at stake, but all of time itself. Can this ragtag team defeat an immortal threat unlike anything they have ever known?