There’s a stabbing, a violent suicide and a disturbing accident involving kangaroo roadkill in the opening minutes of Talk to Me, and from there, the adrenaline rush of this nightmarish collision of the living and the dead rarely lets up. Having made a name for themselves with the online comic horror and action content of their RackaRacka YouTube channel, Australian twin brothers Danny and Michael Philippou vault into features with assurance and imagination, cooking up gut-wrenching thrills that deftly tap into their own background as viral-video sensations. Acquired out of Sundance by A24, the film is thematically a bit thin but doesn’t stint on genuine scares, intensity or revulsion.

About that opening — DP Aaron McLisky displays eye-catching skills with a tracking shot that follows a young man through a crowded party to a locked bedroom door. His shouts all but drowned by thumping techno music, he breaks down the door and attempts to get his distressingly spooked younger brother out of there, screaming at the gathering of partygoers all pointing their cellphone cameras at them. The revelers seem convinced that some Instagrammable freakout is about to happen, and they’re not wrong.

The script by Danny Philippou and Bill Hinzman is in no rush to show how the shocking prologue events connect to the main characters, but it becomes clear soon enough. There’s also a more subtle foreshadowing of what’s to come as 17-year-old Mia (Sophie Wilde) and her surrogate younger brother Riley (Joe Bird) are speeding along, singing at the top of their lungs to Sia’s “Chandelier” when the car hits something. Mia is badly shaken to find a half-dead kangaroo on the road, its agonized groans prompting Riley to beg her to put the animal out of its misery.

It’s the anniversary of Mia’s mother’s apparent suicide. Given the distance that’s opened up between her and her father Max (Marcus Johnson) since that loss, she spends much of her time at Riley’s house, with his big sister Jade (Alexandra Jensen) and their flinty, no-BS mother Sue (Miranda Otto), who works nights and trusts them to act responsibly. But that makes it easy for Riley, who’s 14, to tag along with Jade and Mia to a party.

The main attraction at that get-together is not the usual teen pleasures of alcohol, drugs and sex, but spiritual conjuring. Clutching what’s allegedly the severed hand of a powerful medium, embalmed and encased in ceramic, they contact the dead, initially with the phrase “Talk to me,” before proceeding to “I let you in” for full possession. But the owners of the hand warn that 90 seconds is the maximum; anything beyond that is an invitation to the supernatural occupant to stick around for good. Of course, that inevitably means someone’s going to tempt fate by exceeding the limit.

The script’s sharpest idea is making these brief possessions an addictive high, not just for the person experiencing spiritual transmission — their eyes dilating and their features transforming into a ghoulish mask as they spew cryptic messages — but for the spectators in the room, shrieking with laughter. While supposedly watching the clock, they film each gross-out episode to share on social media.

This raises intriguing issues about a terminally bored youth culture driven to increasingly dangerous extremes to get their kicks and impress their peers. But the filmmakers show disappointingly little interest in exploring the social phenomenon of cool currency at any price. Fortunately, they bring so much energy and macabre inventiveness to the action that most audiences will be too unsettled to notice.

A case in point is a zippy montage of the core characters taking turns with the hand over the course of one especially wild night. The Philippous and their ace makeup and VFX team show their veneration for vintage Sam Raimi in these scenes, playing it for laughs when Jade’s ultra-Christian boyfriend Daniel (Otis Dhanji) falls under the spell of a horny spirit but steadily upping the stakes as the participants grow more reckless. The concept of teenagers being attacked from within is a shrewd device for potent horror.

Initially something of an outsider in the group, Mia’s stock rises as she throws herself fearlessly into the experiment and keeps coming back for more. But the spirits are manipulative tricksters. When one of the younger teens is in the hand’s other-worldly grip, the ghost of what appears to be Mia’s mother (Alexandria Steffensen) communicates with her, resulting in the endangerment of her friend’s life. This causes alarming convulsions and enough terrifyingly violent self-harm to necessitate hospitalization.

While the predominantly young cast is solid, especially Bird as Riley, talented newcomer Wilde does the heaviest dramatic lifting. She wrestles with Mia’s confused feelings about her mother’s death, her role in the near-fatal injuries to her friend and even the specter of that half-dead kangaroo, all while falling prey to her own paranormal visions and bouts of possession triggered by going overtime. But her anguish doesn’t stop her going back repeatedly to the hand, becoming less and less sure whether to trust the living or the dead as she tries to complete the ritual and release the malevolent spirits stuck in limbo.

It’s in the feverish conclusion that the directors’ storytelling gets a touch sloppy, allowing their instincts for heightened supernatural mayhem to get the better of their control in terms of nuts-and-bolts narrative. But Talk to Me remains exciting and scary throughout, amping up the tension with help from Cornel Wilczek’s muscular score and Emma Bortignon’s creepy sound design. The movie deftly stitches its deepest fears around the idea that grief and trauma can be open invitations to predatory forces from the great beyond. It marks a welcome splash of new blood on the horror landscape.