When director JJ Abrams began planning Star Wars Episode 9: The Rise of Skywalker, he felt the loss of star Carrie Fisher keenly.

The actor, who appeared as Princess Leia and, later, General Leia Organa in five Star Wars movies was intended to be the hero of the ninth and final movie. But her tragic death on 27 December 2016 – after completion on the eighth Star Wars movie but before production had begun on the last – ended that dream. And so Abrams set about sketching how he could possibly make this last Star Wars movie work without Leia, its big beating heart.

While planning, Abrams discovered that a cache of scenes featuring Fisher that had been left on the cutting room floor from The Force Awakens. Maybe they could work in The Rise of Skywalker, the director thought. It would require a difficult dance of matching lighting and reshooting dialogue, but it was also, Abrams told Vanity Fair, “the impossible answer to the impossible question”.

Star Wars 9: Carrie Fisher stars in the new trailer for her final role