Whistle

A misfit group of unwitting high school students stumble upon a cursed object, an ancient Aztec Death Whistle. They discover that blowing the whistle and the terrifying sound it emits will summon their future deaths to hunt them down. Chrysanthemum Willet, known as Chrys, arrives at a new school after a turbulent personal history and is assigned to Mason Raymore's former locker. Mason Raymore, a celebrated athlete, is already a lingering presence in the school's collective memory, shaping how students like Dean Jackson interpret anything tied to him. Chrys's cousin Rel Taylor stays close as she tries to settle in, while Dean Jackson, Grace Browning, Ellie Gains, and teacher Mr Craven orbit a growing unease tied to an unfamiliar object found within the locker. As the group becomes increasingly entangled, small disturbances begin to affect their routines, relationships, and sense of safety, pushing them toward an uneasy awareness that something beyond explanation has entered their lives. During a high school basketball game, star athlete Mason "Horse" Raymore (Stephen Kalyn) experiences a series of escalating hallucinations, each depicting a severely burned man emerging from a cloud of smoke. Following the game's conclusion, Raymore retreats to the locker room, where he locates and destroys an artifact stored inside his personal locker. The burned apparition materializes in the shower area and physically assaults him, and Raymore himself catches fire, burning to death in front of his teammate and friend Dean Jackson (Jhaleil Swaby). Months after that incident, Chrysanthemum "Chrys" Willet (Dafne Keen) relocates to live with relatives and begins attending the same high school, where she is assigned Raymore's former locker. Her cousin Rel Taylor (Sky Yang) accompanies her at the school. When Chrys opens the locker, she finds an urn containing a small whistle carved into the shape of a skull. Dean, still mourning Raymore and aware of Chrys's history with drug abuse and the car accident that killed her father, confronts and taunts her in the hallway. The altercation turns physical, and their teacher Mr. Craven (Nick Frost) sends both of them to detention along with Rel, Dean's girlfriend Grace Browning (Ali Skovbye), and Grace's friend Ellie Gains (Sophie Nélisse), who had stepped in to defend Chrys. During detention, the skull whistle slips from Chrys's bag and falls onto the floor. Craven picks it up and inspects the carving, reading the inscription as a phrase he translates to mean "summon the dead." He confiscates the artifact and retains it on his desk. After the students leave, Craven finds records suggesting that similar objects carry significant monetary value, and he blows into the whistle to verify it is still functional. Separately, Rel slips back into the detention room, reviews the research notes Craven had been consulting, and pockets the whistle before leaving. That same evening, Chrys is approached outside by Noah Haggerty (Percy Hynes White), a local youth pastor who attempts to sell her drugs. When Rel intervenes, Noah assaults him. Later that night, a sickly apparition in the physical form of Craven stalks the teacher through his own home and kills him, crushing his lungs from the inside. The death is subsequently attributed by officials to advanced lung cancer, despite no prior record of the condition. The five students from detention gather at Grace's house, and at Dean's urging Grace blows the whistle, producing a painful, disorienting sound that affects everyone present. Chrys grows uneasy and leaves early, but before departing she accepts an invitation from Ellie to attend the Harvest Celebration, a local outdoor festival taking place the following day. On the walk home, Chrys confides to Rel that she is attracted to Ellie. The next morning, the school announces Craven's death. Chrys, Grace, and Ellie each begin to experience a persistent sense of being watched, along with intrusive haunting visions of themselves. Chrys and Ellie take the whistle to the home of Ivy Raymore (Michelle Fairley), Mason's terminally ill grandmother, who maintains a large private collection of occult and antiquarian objects. Ivy corrects Craven's translation: the inscription does not read "summon the dead" but rather "summon YOUR death." She explains that the whistle summons the destined death of every person who hears its sound, and that each summoned death takes the form of the listener at the moment of their dying. Ellie reviews medical documentation from Mason's coroner report and finds that, despite Raymore having been seventeen at the time of his death, his tissue showed the biological age of a man in his late forties. The two return the whistle to Rel and rush toward the Harvest Celebration to warn the others. At the festival, Noah intercepts Chrys and Ellie and threatens them with a knife. Chrys breaks his hand and lacerates his nose, and the two flee into the crowd to locate their friends. Inside a hay-bale maze, an elderly apparition bearing Grace's features stalks her through the twisting corridors and attacks her at the maze's center, causing her to age with extreme rapidity before she dies. Chrys and Ellie find Dean and Rel and relay what they have learned from Ivy, but Dean, heavily intoxicated and unwilling to accept Grace's death, drives away alone. The following morning, a mutilated apparition of Dean haunts him inside his own room, and he dies from the catastrophic internal and external injuries consistent with a severe car accident, without ever having left his home. Chrys, Ellie, and Rel return to Ivy's residence to seek further guidance. Ivy, now bedridden and deteriorating rapidly, tells them that death can be redirected by offering another soul in the condemned person's place, accomplished by marking the substitute with the cursed individual's blood. She dies shortly after delivering this information. Rel immediately breaks away from the group and drives toward Noah's church. Chrys discloses to Ellie that she had previously overdosed on drugs, and that her father died in a car crash while driving her to the hospital in response, a death for which she holds herself responsible. The two kiss. At the church, Rel subdues Noah at gunpoint and transports him to the steel mill where Rel is employed, the same location he had seen in a vision depicting his own death. Rel prepares to draw his own blood and mark Noah with it. Chrys and Ellie arrive and persuade him to stop. Moments later, an invisible industrial grinder activates around Rel and kills him. Chrys recognizes that the condition Ivy described, dying, may not require permanent death. Working from Ellie's diabetic medical supplies and the equipment available at the mill, they formulate a plan to stop Chrys's heart using an injection of Ellie's insulin followed by submersion in an ice bath, then restart it using an AED defibrillator. Ellie administers the insulin injection to Chrys without warning and pushes her into the ice bath before Chrys can object. Submerged and unconscious, Chrys encounters a terrifying vision of her own double beneath the water and struggles against it. Noah, having freed himself from his restraints, locates Rel's discarded firearm and fires at the AED unit, disabling it, and the bullet also grazes Ellie's side. With the defibrillator compromised, Ellie fights through visions of her own approaching death and, using the damaged equipment, manages to revive Chrys. Ellie then collapses to the ground in a diabetic seizure from the blood loss and physiological stress. Noah crosses the floor toward the two and inadvertently presses his fingers into the blood pooling from Ellie's wound. The curse immediately transfers to him. Ellie's seizure stops, her approaching apparition withdraws, and a bloated, decomposing version of Noah descends on him and kills him. Three months later, Chrys and Ellie are in an established relationship. In a mid-credits sequence, a new student at the school opens her assigned locker, discovers the skull-shaped whistle inside, and blows it in front of a packed school assembly.