Plot
A paramedic rescues a young girl from the blazing Saint Luke's hospital before unsuccessfully inquiring about her mother's whereabouts. Sometime afterwards, undergraduate Shelley Baum hears her cat meowing near her house's koi pond. After she heads over to investigate, a hand appears and drowns her and her cat. Days later, college students Beth Raymond and Leann Cole discuss Shelley's funeral. Leann's cellphone rings in a lullaby-esque ringtone, with a call from Shelley. She opens it to an eerie voicemail of herself, dated June 12 at 10:17 PM. Subsequently, suffering from disturbing hallucinations, she calls Beth while returning from a study session. Beth rushes to her location but arrives just as Leann falls off an overpass and is struck by a train. A red candy pops out of her mouth, and her severed hand dials a number on her phone. At Leann's funeral, her ex-boyfriend Brian Sousa departs after experiencing hallucinations. Outside a coffee shop, he shows Beth Leann's post-mortem voicemail, dated minutes away. An acetylene tank explosion from the adjacent construction site launches debris into the air, and a rebar impales Brian's torso. A red candy is ejected from his mouth, and he collapses.
The next day, Beth meets police detective Jack Andrews, who mentions that his sister Jean interned with Shelley at Saint Luke's and died herself two days prior. They determine the events are interrelated and he provides his contact card. Beth consoles her friend Taylor Anthony, who is distraught by a premonitory feeling of being the next victim, so Beth removes the batteries from both their cellphones to disable them. That night, Taylor's cellphone rings; she opens it to see a video of her apparent demise. The following morning, Jack and Beth research geriatric nurse Marie Layton, originator of the calls, and find the autopsy report of her eldest daughter Ellie, who died from an acute asthmatic episode. The file, mentioning "no bruising but evidence of past scars" with an attached CPS file for further consultation, indicates that Jean, a psychiatric nurse, questioned Marie at Saint Luke's and noted nine admissions between April and May for Ellie and her sister Laurel, concerning several causes, leading Beth to assume that Marie had FDIA.
Meanwhile, TV producer Ted Summers, who approached Taylor earlier, prepares to record her exorcism, explaining that spiritual energy operates in the same electromagnetic spectrum as light/microwaves and is therefore transmissible via cellular phones from which it manifests as hallucinations. Noticing the show's advertisement on TV, Beth races to the site, arriving to an unseen force fatally choking Taylor. Her phone then sounds with a voicemail dated for tomorrow. Taking Beth home, Jack learns about her past in which her mother was abusive towards her (in particular burning her daughter with cigarettes), and her father, aware of his wife's abuse, hanged himself in their house's attic.
Assuming that finding Marie will settle the matter, she ventures to Saint Luke's and encounters Jack. As they enter an operating room, Marie's spirit ejects and incapacitates Jack. Locked inside, Beth throws a chiming phone across the room, where it knocks the air duct's grill cover loose, revealing a crawlspace. Inside, she discovers Marie's charred corpse clutching a cellphone. Marie's corpse awakens and, after pursuing and intercepting Beth, weeps and murmurs, "Forgive me." Subsequently, Beth tells Jack that Marie might have brought her there to protect her.
At Laurel's foster home, Jack uncovers a compact disc from the nanny cam embedded in the eye of Laurel's teddy bear. The footage reveals Ellie incising Laurel with a knife in their bedroom. Marie entered shortly thereafter, discovered Ellie's abusiveness, and rushed Laurel to the hospital. Ellie, locked inside, began pressing wheezingly on the inhaler but was overwhelmed and collapsed, facing the future curse's constituents (millipedes, an uncanny doll of a mother with baby in a perambulator (hallucinations), and the lullaby-esque music emanating from the teddy, audible during every victim's call), before dying from asphyxia while dialing her mother's phone number. Laurel reveals that though Ellie injured her, she always provided candies. Realizing Ellie caused the curse, Jack drives to Beth's house, during which a colleague informs him of a new voicemail. After he enters, somebody knocks on the door. As he peers through the peephole, a knife stabs through it, killing him. Ellie appears and attacks Beth, but Marie's spirit intervenes, binds Ellie in Jack's phone, and reconciles with Beth before evanescing. Jack's mouth spills a red candy and his cellphone auto-dials, revealing that the curse is still active.