'Relic' is a tense new horror movie that contains a poignant message about dementia

• Warning: Minor spoilers for "Relic" ahead.
• "Relic" is a new horror movie that touches on the challenges of losing a loved one to dementia.
• The film focuses on Edna, the aging matriarch of a family, as she's visited by her daughter Kay and granddaughter Sam.
• Kay and Sam find evidence that Edna has dementia as well as something much more terrifying.
• The movie is directed by Australian-Japanese director Natalie Erika James and premieres in theaters on July 10.

Those who've lost a loved one to dementia know how excruciatingly painful the struggle can be. Innocuous lapses in memory, like forgetting to pick up dry cleaning or pay a bill, eventually morph into something that becomes much more heartbreaking — and, in the case of "Relic," more sinister.

The new horror movie from Australian-Japanese director Natalie Erika James focuses on three generations of women all affected by dementia: Edna, the matriarch who's recently gone missing, her daughter Kay, and Kay's daughter Sam. When Kay and Sam arrive at Edna's home after her disappearance, they find notes and other odd things around the house, leading them to believe that Edna's been struggling with dementia for a while.

Edna does return, but her homecoming raises more questions than answers for Kay and Sam, who's fiercely protective of her grandmother. As Edna's mental state continues to deteriorate, it becomes apparent that something — or someone — has taken over their beloved family member's mind and body.

What it's about: 'Relic' follows Edna and her family members as they struggle to save her from an evil force

Most of the movie takes place in Edna's cluttered home and the surrounding forest, both of which grow more and more ominous as the film goes on.

And while they both arrive at Edna's home united in their determination to save her, Kay and Sam's relationship slowly begins to crack. Sam has a loving and nurturing relationship with her grandmother, who tells her stories about her childhood and even gives her a family heirloom ring. Kay, on the other hand, often loses patience with her mother, berating her to the point where Sam has to step in.

Kay and Sam are also at odds about how to best care for Edna. Her granddaughter offers to move in and help with Edna's care, but Kay is adamant that Edna be placed in a home, where she'd likely be safer and less of a burden.

The tensions between mother and daughter, however, are quickly put aside after it becomes clear that Edna is under the control of something much more sinister than a debilitating disease. After shouting at Sam and ripping the ring from her finger, Edna spirals further and further into madness, eventually chasing both Sam and Kay up to the attic, which has mysteriously morphed into a dark, labyrinthine, and decaying space.

Sam and Kay eventually manage to defeat the now-monstrous version of Edna, but after nearly fleeing the house, Kay turns back to spend one last moment with her deceased mother — much to the distress of Sam.

Why you should watch: The movie deftly portrays the struggles of caring for someone with dementia while also providing genuine scares

Ultimately the true horror of "Relic" is the clever way it shows the struggles people with dementia (and those caring for them) face.

Edna's disorientation and frantic notes to herself mirror behaviors exhibited by many dementia patients in real life. As Kay and Sam are drawn further and further into her paranoid mindset, the house begins to reflect that: Objects shift inexplicably, ominous shadows appear, and even the previously well-lit attic turns into a terrifying labyrinth.

It's not an easy watch for precisely this reason, but as someone who lost a grandparent to the disease, it was cathartic, in a way, to see dementia portrayed as the life-destroying evil it eventually becomes.

The bottom line: 'Relic' is a terrifying film that cleverly touches on the real-life horrors of dementia

With a chilling plot, a creepy house, and a suffocating amount of tension, "Relic" isn't for the faint of heart. But the film's poignant exploration of dementia is unforgettable — and even though the tense family drama and deluded old ladies call to mind movies like "Hereditary," "The Babadook," and "The Taking of Deborah Logan," "Relic" is in a whole other league of its own.

Grade: A

"Relic" will be released in theaters July 10. You can watch the trailer below.