As anyone who has seen the new Star Wars spinoff Rogue One will know, the movie is packed with Easter Eggs, cameos, and callbacks to the other films in the blockbuster series. Now director Gareth Edwards has spoken about one of the coolest surprise appearances.

　　Spoilers about Star Wars: Rogue One follow below.

　　In an interview with the Radio Times, Edwards discussed the appearance of Rebel pilots Red Leader and Gold Leader from the original Star Wars. The director revealed that the footage of the two characters--played by actors Drewe Henley and Angus MacInnes--were actually taken from unused scenes from the original movie.

　　"We went to Skywalker ranch, and there's the archives there," he said. "And as we're walking around, and doing all the cool things and looking at the Millennium Falcon and trying on Han Solo's jacket and things like that, in the back at the bottom was all these cans of film. And we said, 'What are they?' and they said, 'Oh, it's Star Wars.' "And you go… 'has someone gone through all this? And it's like, 'not really, they're not fully digitised at all.'

　　"We got the neg documents and found the clips from A New Hope that hadn't been used. And there's pilot photography and lines that were never featured in [the film.] Through the magic of [vfx studio] ILM they cut round them and manipulated them and stuck them into our cockpits."

　　Edwards went on the explain that he wasn't initially sure the time, cost, and effort involved in placing the characters into the climactic scenes of Rogue One was worth it--until he saw the movie with an audience.

　　"It's the sort of thing you think, 'How many people will notice?'," he admitted. "It's like, is this a lot of effort for very little reward? At the world premiere in LA, there was this massive cheer at a particular point in the film. It was the only time during the premiere where I actually punched the air."

　　Rogue One opened last weekend to massive worldwide success. In the US it made $155 million, which makes it the second biggest December opener of all time, behind last year's Star Wars: The Force Awakens. Internationally, it earned $135.5 million, boosting the global haul to $290.5 million. Check out GameSpot's review here, and read our roundup of the best moments from the film.