Arrow-Flash spinoff synopsis and airdate: First trailer of Legends of Tomorrow may air during The Flash finale?

The CW Network has confirmed that Arrow and The Flash spin-off will be titled DC's Legends of Tomorrow.

The series will revolve around The Atom, Firestorm, Canary, Rip Hunter, Hawkgirl and an unidentified "mystery hero", and will air on The CW in the fall of 2015-16.

The network has also released the first official synopsis for the series, which reads as follows:

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?

The DC Legends cast will include characters of The Flash and Arrow like Victor Garber (The Flash) Brandon Routh (Arrow), Caity Lotz (Arrow). Arthur Darvill, Ciarra Renee, Franz Drameh will star alongside Dominic Purcell (The Flash) and Wentworth Miller (The Flash).

The series is being produced by Greg Berlanti, Marc Guggenheim, Andrew Kreisberg and Sarah Schechter.

According to a new report, the first promo of the Arrow-Flash spin-off series might air during the finale of The Flash, which will air on 19 May and may introduce some of the spin-off characters.

Ciara Reneewill who will play Hawkgirl, teased that she will appear in the season finale of The Flash.