“Some cultures believe that . . .” Oh Lord. Not this again. You know the makers of a horror film are getting desperate when they drag out an expert to argue that the unscary monster has been seen in cave paintings and Egyptian hieroglyphs.

By the time Dr McBoffin pops up, even the most committed fans of the first Sinister film will have checked out. We are delighted that Ciarán Foy, director of the cracking Irish horror Citadel, has his feet under the franchise table, but he has been handed a cluttered, tonally deranged mess of a script. No amount of nicely murky atmosphere can save it.

It is odd to report that the film is at its best when it is most like a Nicholas Sparks adaptation. Shannyn Sossamon (now where have you been, madam?) plays a mom fleeing an abusive husband with her twin children. We know the husband is a monster because, like the drunken stepdad in Boyhood, he forces his son to play golf at the weekend.

Sossamon takes shelter in a big old house where she is eventually joined by a kindly paranormal investigator (James Ransone). The actors are all fine. If the film were set in North Carolina and called something like My Heart is a Falcon, then it might progress tolerably to a soppy conclusion.

Unfortunately something eerie, supernatural and boring is happening in the basement. Scary, starey children are emerging from the woodwork and forcing the twins to watch ancient footage of grisly murders that involve a ghoulish Michael Jackson impersonator.

I saw and liked Sinister, but even I was profoundly confused until, about an hour into the action, the script reminds us of that film's significant twist. Those unfamiliar with the opening section will be even more lost. Having paid to see a horror film, audiences will be further puzzled by the apparent assertion that repeated exposure to scary movies can turn children into homicidal maniacs. Even if that were the case, parents would have nothing to fear from Sinister 2.