Director Rodney Ascher is best known for Room 237, his account of the multifarious fan theories surrounding The Shining, one eyebrow gently raised throughout. Now with A Glitch in the Matrix, another beloved movie becomes his muse, the 1999 sci-fi classic in which Keanu Reeves abruptly woke from the amniotic fugue in which he and the rest of humanity were unwittingly trapped. Rather than a mere celebration, however, Ascher instead treats The Matrix as the jump-off for a study of the simulation theory it helped popularise — the troubling notion that we are all Keanu Reeves, every last atom of our reality the creation of a computer programme.

Most uneasy of all may be what some see as the statistical improbability that it could be anything but, a sub-theory that even withstands being voiced by Elon Musk. Still, as with his previous movie, Ascher is ultimately less concerned with the ideas than with the people swept up in them. In that he has plenty of candidates. Long before Reeves, the film traces simulation theory back from author Philip K. Dick through René Descartes and into the birth of Christianity. After all, one interviewee says, what are the gates of Saint Peter if not a celestial red pill? You may now say: “Woah”.

★★★☆☆

On digital platforms in the UK from February 5