Of all the isms, ageism might be the most baffling. If we're lucky, we're all going to be old some day so discriminating against the elderly means we're only making things tougher for our future selves. It's like if white people knew they were going to turn black when they hit 65 yet continued to be racist. And yet, possibly because of its disconnect from race, gender or sexuality, ageism is the most acceptable and unquestioned form of prejudice, so much so that in our supposedly enlightened modern times we still get movies that mock the elderly for cheap laughs.

That's exactly what we get with The Front Room. Written and directed by Max and Sam Eggers (brothers of The Northman director Robert) from a short story by 'The Woman in Black' author Susan Hill, The Front Room is a sloppy mashup of two horror subgenres. It's part hagsploitation, featuring as it does an elderly female antagonist, and part Rosemary's Baby-esque pregnancy horror. Except it doesn't function as a horror movie whatsoever, preferring as it does to generate gross-out gags at the expense of the elderly.

When pregnant Belinda (Brandy Norwood, best known to R&B fans as simply Brandy) quits her college teaching job due to racist treatment by the administration, it leaves herself and her husband Norman (Andrew Burnap) in a bit of a financial pickle, struggling to pay off their mortgage. Their economic woes end when Norman's father passes away and his elderly stepmother Solange (Kathryn Hunter) decides to pass on her inheritance to Norman and Belinda. But it comes with a significant codicil: they will only receive Solange's money if they allow her to move into their home.

Norman tries to explain to Belinda just what a looney tune Solange is, claiming she regularly traumatised him as a child with her Christian fundamentalist ways, but Belinda convinces him that the end to their money troubles will make the old bat worth putting up with. How bad can she be?

Pretty damn bad, as it turns out. Solange is barely in the door before she's disrupting Norman and Solange's lives. Claiming she can't negotiate stairs, she insists that she move into the ground floor front room they had planned as a nursery for their unborn child. She mocks Belinda's choice of a baby name and convinces her to change it to one of her own choosing. Belinda is subjected to racist micro and not so micro aggressions. Solange fills the house with furniture that wouldn't be out of place in the Bates house. But what really bothers Belinda is Solange's seemingly supernatural awareness of details she hasn't been made privy to, like the loss of Belinda's stillborn son a couple of years ago. In classic Mia Farrow fashion, Belinda begins to fear that Solange has sinister intentions towards her unborn child. And in classic John Cassavetes fashion, Norman begins to take Solange's side.

Solange is indeed a monster, but for all her racism and creepy Christianity, the film is more concerned with her incontinence as a means of demonising her. The Eggers childishly revel in giving us scene after scene of Solange shitting herself, their camera dwelling on soiled sheets and close-ups of flushing toilets and brown stains on every surface. For Belinda and Norman, the worst thing about Solange is something she can't control, something which will afflict a lot of us if we reach a certain age.

But as much of a monster as Solange may be, Belinda and Norman don't have a moral leg to stand on. It's impossible to sympathise with this couple who gladly took Solange's money and are now finding they have to earn it. Whenever Solange hints that they've made their soiled bed and now have to lie in it, you can't help but nod along with the old biddy. Most of us have had to share a dwelling with someone we didn't get along with because we couldn't afford a place of our own, so I can't imagine too many viewers will have much sympathy for the entitled Belinda and Norman.

The biggest problem with The Front Room is that it doesn't know whether it's a supernatural thriller or a glorified '70s sitcom. The supernatural aspect is largely forgotten about at a certain point, and the special powers it's hinted Solange has in her locker make the final twist a head-scratcher. Hunter certainly seems to believe she's in a comedy, with a hammy performance that will require subtitles for those of us who weren't born south of the Mason-Dixon line. Conversely, Brandy is barely awake, never reacting to the escalating scenario with the level of emotion it requires. For all its hamminess, The Front Room somehow resists the temptation to give Belinda a male child, denying us the moment where she confronts Solange and Brandy defiantly declares "The boy is mine!"

Directed by: Max Eggers, Sam Eggers

Starring: Brandy Norwood, Kathryn Hunter, Andrew Burnap, Neal Huff