HERE’S ALL you need to know about this extravagantly atrocious contribution to the scary child genre of horror film. About two thirds of the way through, Rabbi Gary Oldman gets to blow a large ceremonial horn while performing an exorcism. That’s the sort of picture we are dealing with. The sort of picture where Gary Oldman wields a ceremonial horn.

What are you up to, Oldman? I know times are hard, but there are, surely, more dignified ways of scraping together the rent. You could sell an organ. You could become a sandwich-board wearer. Must you really take the roles even Cuba Gooding Jr has turned down?

Anyway, The Unbornis about as bad as horror films get without turning good again. Odette Yustman (an unsettling amalgam of Megan Fox and Jennifer Connelly) stars as a young woman who spends her days running away from a juvenile ghost while wearing nothing but her knickers. "Jumby wants to be born now," the spooky child says.

Eventually, after one too many near-nude traumas, Odette consults a doctor and learns that she was conceived as a twin and that her brother died in the womb. Yeah, you’re way ahead of me. There’s also a lot of stuff about Jewish myths and some gibberish concerning a dog with an upside-down head.

The Unbornis, for the most part, harmless, undemanding idiocy, but, when the plot begins to reference the Holocaust, a distinctly dubious atmosphere spreads about the place. "It's up to us to finish what started in Auschwitz," one character says. I think that's what you call – in the context of horror cinema – the wrong type of bad taste.

Directed by David S Goyer. Starring Odette Yustman, Gary Oldman, Cam Gigandet, Meagan Good, Carla Gugino, Jane Alexander 16 cert, gen release, 87 min★