There’s the seed of a promising premise at the heart of “The Lullaby,” a modern tale of Gothic horror from South Africa. It’s just a seed, though. An incoherent and obscure script, unrestrained hysteria in the performances and inept “gotcha” execution let that seed rot in the ground.

A prologue shows us Boers — white South Africans — stuffed into history’s first concentration camps during the Boer War at the start of the 20th century. Women wail, as they’ve been raped by their British captors. A helpful preacher intervenes. He wrings their rape babies necks and tosses them off a cliff, “Eden Rock.” Needless to say, this doesn’t help the mothers’ states of mind.

In Eden Rock in the present day, Chloe (Reine Swart) is a troubled 20ish young woman with Ricci eyes and Cara DeLevingne eyebrows whom we see give birth. Her mother Ruby (Thandi Perun) brings Chloe and little baby Liam home from the hospital, and asks one question.

“Who’s the dad?”

Chloe’s not telling. Mom is irked — “You’ve done this to SPITE me.”

And she’s alarmed. Chloe’s missing a few mothering instincts. Like all of them. The baby is being neglected, mishandled even when he’s being coddled.

When Grandma Ruby is away, things turn worse. Chloe has visions — of killing her baby, lopping off his toes when she’s supposed to be trimming his nails, of demons on the static-filled TV or in the shadows, coming to steal her baby.

Mom’s lepidopterist shrink (Brandon Auret) isn’t the solution to their problems. He may be the creepiest psychotherapist the movies have ever produced, and not just because he enjoys poking pins in butterflies.

“I’m a collector. I collect…things.”

So we the audience can make connections between the horrors of the past and the haunting of the present, even if Chloe can’t. Her mother’s lullabies should more overtly tie the prologue to the main story thread, but doesn’t.

The terrors Chloe fantasizes will eventually become reality, and she’s not the only one seeing this. But the shrink is mysteriously “Let things run their course” passive. And Ruby keeps leaving her grandbaby in the care of a girl who has to be reminded, “Don’t forget to FEED him.”

The only hair-raising moments come early on, glimpses of shadows that instantly send Chloe over the edge. There’s no rising realization of horror in her mind. She jumps straight into freak-out mode. And young Ms. Swart plays that bug-eyed mania, from start to finish.

Director Darrell Roodt does nothing to build suspense and little to build empathy for the character. Only the helpless baby earns our pity, and that’s because he’s not old enough to have a better agent.

Nor does Roodt spell out the connections between the adults in the story and the village’s horrific past, though that’s obvious enough to pick out visually.

There was promise in the set-up, which surprisingly makes the racist, Dutch Nationalist Afrikaans the victims despite the fact that they’d rather kill their babies than raise British bastards. Those opening horrors should burn into our memory and carry the succeeding picture off.

But for an SUV load of reasons — budgetary, acting prowess, camera placement, cutting — they don’t. And the unfrightening film that follows just underlines that with every fresh shriek and scream.

MPAA Rating: unrated, graphic, bloody violence

Cast: Reine Swart, Thandi Perun, Brandon Auret

Credits:Directed by Darrell Roodt, script by Tarryn-Tanille Prinsloo. An Uncork’d Entertainment release.

Running time: 1:26