April 19, 2015 4:05 PM EDT

Star Wars fans learned some good news Sunday: the plot of the first spinoff film Rogue One.

The revelation was timed to coincide with Star Wars Celebration, a fan festival in Anaheim, Calif.

Rogue One, which takes place between Episode III and IV of the film series, stars Felicity Jones and hits theaters in December 2016. It’s the first spinoff of the popular franchise and will release a year after Star Wars: The Force Awakens.

Write to Justin Worland at justin.worland@time.com.

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