The Star Wars stand-alone films that Lucasfilm is developing outside of the episodic series will be called Anthology films, Lucasfilm vice president of development Kiri Hart announced at Star Wars Celebration today. The director of the first of those stand-alone films, Gareth Edwards, also brought new footage and story details from the first spin-off movie, which is now officially titled Star Wars Anthology: Rogue One.

While filming hasn't actually started on Rogue One yet, Edwards said, he showed some pre-production footage created by Industrial Light & Magic of a TIE Fighter flying over a jungle planet, with a shot of the Death Star set in the distance.

Lucasfilm also revealed the official plot synopsis for the film:

A rogue band of resistance fighters unite for a daring mission to steal the Death Star plans and bring new hope to the galaxy in the Star Wars Anthology film, Rogue One.

Edwards says Rogue One is set sometime after Episode III: Revenge of the Sith, but before Episode IV: A New Hope. The director said that the film will focus more on the Rebels, and not the Jedi. He also confirmed that actor Felicity Jones will play a rebel soldier.

"It comes down to a group of individuals who don't have magical powers that have to somehow bring hope to the galaxy," Edwards said.

The story of Rogue One won't be as black and white as other Star Wars films, Edwards explained, but will have shades of grey. The director said they're going for a "real" approach to Star Wars.

Edwards and company also showed a piece of concept art for Rogue One, which featured a squadron of Rebel soldiers running through the rain, with an unfamiliar-looking ship behind them.

The story of Star Wars Anthology: Rogue One was pitched by ILM chief creative officer John Knoll, who presented the idea to Lucasfilm president Kathleen Kennedy and Hart. They approached Edwards with the idea while he was still working on Godzilla. After Edwards read the pitch, he said, "I couldn't sit in a cinema and know that someone else made this film." So he signed on.

Working with Edwards on Rogue One are special effects supervisor Neil Corbould, production designers Neil Lamont and Doug Chiang and cinematographer Greig Fraser. Their credits include work on films like Black Hawk Down, Zero Dark Thirty, Saving Private Ryan, Edge of Tomorrow and the Harry Potter series.

Earlier in the panel, Kennedy said Lucasfilm wanted "freedom to do some films that would ... tell their own stories and vary in scale and genre." Hart later added, "I think this as opportunity for us to tap into emergent directing talent out there and do some things that are unexpected."

Star Wars Anthology: Rogue One is set to begin filming this summer in the U.K. and other unannounced locations.

Low quality footage of the teaser was captured by a Star Wars Celebration attendee, which you can watch below.