The Substance” blowtorches a single idea for two hours and 20 minutes, and narratively it turns to ashes by minute 40. It’s easier for a movie to become a talking point that way. Film festival buzz, which “The Substance” enjoyed at its Cannes world premiere,

Finally, “The Substance” is very much a woman’s movie. The way writer-director Coralie Fargeat presents Demi Moore and Margaret Qualley — the matter-of-fact way in which she films their bodies, and the trust that she elicits from them — has the unmistakable stamp of a woman director. This is obvious within minutes.