Whedon’s poignant, cheeky space western was adapted from Firefly, a cancelled television series that — as its garrulous creator notes in the DVD extras — “hardly anyone saw”.

Whedon’s attempts to resuscitate his baby reached desperation point — he remembers commenting to a colleague: “At what point does this stop being CPR and start becoming necrophilia?” But, on the back of prodigious DVD sales, Firefly was reborn as Serenity, a film that combined the tropes of Star Wars, Star Trek and Alien with the witty, humanistic dialogue of Whedon’s own Buffy and Angel. Let this be a lesson to you, George Lucas: in science- fiction cinema, it is quite possible for the writing to be as lively as the visuals.

DVD extras

Commentary by Whedon, four documentaries, deleted scenes, outtakes

ED POTTON