The subject of Charles Manson and his murderous cult killings continues to be a subjective of obsessive interest. To add to the existing mountain of pop-culture Mansonbilia, Sean Durkin‘s 2011 film Martha Marcy May Marlene was inspired by Manson, and Quentin Tarantino’s forthcoming Once Upon A Time In America is set during Manson’s reign of paranoia.

Now screenwriter Guinevere Turner and director Mary Harron, usually such fierce anatomists of masculine toxicity in the movies they made together like American Psycho (2000) and The Notorious Bettie Page (2005), have taken on the same subject with Matt Smith as Manson, the creepy, pompous failed pop star and cult leader whose word is law for beaming disciples. But the result is a weirdly bland and inhibited TV movie, flatly directed and fundamentally constrained by its fence-sitting inability to decide if Manson’s obedient female slayers were essentially victims or murderers of equal culpability. It has none of the brilliance and insight of Emma Cline’s 2016 novel The Girls, on roughly the same subject.

Harron makes her focus three of Manson’s women: Leslie Van Houten (played by Hannah Murray — Gilly from Game Of Thrones), Patricia Krenwinkel (Sosie Bacon) and Susan Atkins (Marianne Rendon). It is the early 70s and they are in prison, doing life for the Manson crimes, and — according to this film — allowed adjoining cells and allowed to associate together. The movie imagines an idealistic grad student Karlene Faith (Merritt Weaver) who runs an adult education class in prison; she tries to dispel the bizarre delusions that the Manson women still cling to about the end of the world being nigh and Charlie being the one to save them, and even teach them about feminism. The movie flashes back to their time with Manson at his remote ranch.

This is portrayed convincingly enough. Matt Smith’s Manson is the gimlet-eyed patriarch-abuser and poundshop Messiah, with requisite hair and beard, strumming on the guitar and singing his excruciating songs and often comparing himself to “ol’ JC”. His moods will turn on a sixpence from genial praise to terrifying rage and he has the natural leader’s skill in Führerkontakt, focusing his flattering attention with devastating force on one acolyte before sweeping it mortifyingly away to someone else, playing one follower off against another and diffusing the sexual tension among the group.

Tragicomically, but rather horrifyingly, Manson was a wannabe pop star whose entire homicidal career might well be explained by rage-filled humiliation at failing to land a record contract. The film shows his acquaintance with the Beach Boys’ Dennis Wilson (James Trevena-Brown) which got him a writing credit on an obscure Beach Boys song and this gruesomely fascinating fact is the poisonous entrypoint for pop culture Manson obsession: did Manson have a kind of writer’s credit on the whole disillusioned late 60s Zeitgeist? (There is an urban myth that Manson auditioned for the Monkees. A more subversive film could be made about just this idea, with Smith perhaps reprising his Manson turn, and Johnny Knoxville, Steve Coogan, Bill Hader and Paul Rudd playing the Monkees.)

The women all have the same seraphic, sweetly tolerant haze in their cheesecloth and denim, coolly murmuring phrases like “far out” to indicate cowed approval of everything Manson says and does. Harron conjures up the central hypocrisy of the permissive sexual revolution: it was for guys only. The men called the shots. Some of the meal scenes reminded me interestingly of The Handmaid’s Tale. Manson’s followers are well acted, and first among notional equals is Hannah Murray as Leslie (renamed “Lulu” by Manson), her gentle, beautiful face becoming a mask of uncomprehending sadness.

But the film can never quite decide how to dramatise the unarguable fact of their participation in murder, and there is a rather absurd scene in which Leslie, bullied into taking part, scrunches up her face with distaste and stabs away at a victim who is out of frame, like someone getting on with a yucky job. Well, maybe that was what it was like and of course Manson is the key villain. But reducing the women’s full adult responsibility infantilises them and actually makes them less interesting. Well — strong performances from Matt Smith and Hannah Murray for all that.