It’s not a blanket condemnation to say I could not wait for “Bring Her Back,” the excruciating new film from the co-directors of “Talk to Me,” to come to an end.

One can recognize its unflinching, grisly details and unsparing cruelty and appreciate that it’s not played for grisly horror laughs or even intended to “entertain.” But this is as hard a movie to sit through as they come — flesh-rending, tooth-shattering violence filmed in sadistic, gory closeup, victims pitilessly victimized over and over again.

The victims are children. The victimizer is an adult and a “system” that carelessly lets children fall into the wrong hands.

“Bring Her Back” is a movie anchored in loss and grief, but only truly heartbreaking when we see the consequences of that visited upon those least prepared to handle it and fight back against their abuser.

Piper (Sara Wong) is an isolated Aussie tween, someone who can’t make friends easily. At least her older stepbrother Andy (Billy Barratt) is there to look out for her, make sure she gets home from the bus stop safe and sound.

Piper’s blind. So Andy is the only one to see the awful, bloody death throes of their father in the shower when they get home.

The devastated duo is thus surrendered to “The System,” which in this small-town corner of Australia means they’re fostered out to a former counselor. Laura (the great Sally Hawkins, pushing the envelope again) seems kind and nurturing. For about a second.

In no time, we see how she manipulates both Andy and Piper — their memories, their relationship with their shared father and with each other — focusing on the ugliest possibilities, making each paranoid about the other and what they “know” about their past and their family.

Laura’s been through loss herself. Her daughter Cathy died not long ago. And she’s got another foster child already under the roof of her isolated house in the rainforest. Oliver, “Ollie” (Jonah Wren Phillips) is mute and seemingly locked away. But if he could talk, the stories he might tell…

Sibling filmmakers Danny and Michael Philippou let us glimpse video tapes Laura is watching. They’re not just old home movies of Cathy (Misha Heywood). She’s watching creepy Eastern European rituals, “how-to” videos of the most disturbing nature. She’s prepped the house with a vast white circle in chalk that you can only see from above, and painted a DIY depth line on the side of her pool.

Whatever Laura is prepping, you can bet it won’t be to any living child’s benefit if the title “Bring Her Back” tells us anything.

Hawkins, of “The Shape of Water” and “Happy Go Lucky,” has a nurturing innocence and sweetness that the Philippous tap into and flip on it’s head for this role in this film. Laura couldn’t possibly be capable of this or that. Oh yes she is.

The Philippous put children in the most wrenching jeopardy one could imagine and tease us along to see if the kids — or any one of them — figure out the nature of the threat and who embodies it in time to save them all.

It’s the filmmakers’ unsparing depiction of violence against children that overwhelms this story of supernaturalism or desperate, misguided superstition. That seems excessive, a shock-value cheat that gives this “wrenching nature of loss and grief” story a sense of overkill.

They’ve made a smart, thought-provoking but ugly and incredibly hard to watch thriller in which the crimes against the flesh and teeth overwhelm a simple gothic tale of a mourning mother turned monster and the children The System lets have for her nefarious purposes.

Rating: R, gruesome violence, “bloody content,” nudity, alcohol abuse, profanity

Cast: Sally Hawkins, Billy Barratt, Sara Wong, Jonah Wren Phillips, Misha Heywood and Sally-Anne Upton.

Credits: Directed by Danny Philippou and Michael Philippou, scripted by Danny Philippou and Bill Hinzman. An A24 release.

Running time: 1:44