Iona, a young mother, flees Glasgow with her 15-year-old son Bull after he kills his abusive partner, whom Bull had believed was his father. They head for the island of Iona, the place where she was born and raised, hoping the seclusion of the island will shield them from a past that has become unbearable. Upon arriving, they burn the partner’s body inside their car, a desperate act to sever the chain of violence and memory, but Bull is consumed by guilt for the life he has taken and the father he never truly knew.
They arrive unannounced at the home of her former adoptive father, Daniel, who had once taken in Iona after her parents abandoned her and raised her alongside his own daughter. Daniel’s wife, Helen, had died years earlier, but his memory of their complicated past with Iona remains. Daniel reveals that he had an affair with the teenager Iona, and she became pregnant with Bull. After their secret was exposed, Iona left them and raised Bull in Glasgow, concealing from him the truth of his paternity. Daniel tells Iona that Helen is gone, and then, with a quiet acceptance, allows Iona and Bull to stay at his island home, a temporary haven from the storm that has defined their relationship.
The island welcomes Iona back into a tight-knit Celtic Christian community, a culture steeped in tradition and ritual. On this small island, Iona reconnects with Elisabeth, Daniel’s daughter, who is now married to her childhood sweetheart Matthew and mother to a 14-year-old daughter, Sarah, a paraplegic whose presence is a quiet, steady heartbeat in the family. Matthew takes Bull under his wing, offering guidance and mentorship, while Sarah’s shy flirtations with Bull inject a complicated dynamic into the household. Meanwhile, the longtime bond between Daniel and Iona is rekindled, resurfacing amid the pressures of church and family secrets.
As the community gathers for worship, Iona shares intimate details of her past, including how her mother had moved to the island with a boyfriend to overcome addictions, only for that relationship to fall apart and leave her mother to raise Iona on the island. Bull, still raw from his recent actions, asks questions about faith and forgiveness, and his curiosity about the island’s religious world becomes a flashpoint for Iona, who chastises him for mixing belief with a past he barely understands.
One night, Bull confesses to Matthew in a moment of vulnerability, admitting that he killed his “father” and seeking some form of absolution. The moment is heavy with unspoken consequences, and before Matthew can respond, Iona arrives with news that Daniel has collapsed from a seizure—news that will alter the course of every family member’s future. Daniel’s death weighs heavily on Elisabeth, who lingers with his body in the quiet hours that follow.
Elisabeth’s sorrow peels back layers of family history as she confronts Iona about her years-long secret—her affair with Daniel and the truth about Bull’s paternity. Their sisterly bond is strained but not broken, and they begin to re-knit something fragile and hopeful, even as Matthew’s arrival on the scene complicates matters further. Outside, the mainland police, summoned by Matthew, close in, interrupting the fragile moment of reconciliation and forcing Iona to move quickly to find Bull.
The island’s tension intensifies as Sarah hints at Bull in intimate spaces, pointing him toward her family’s barn where their dangerous, charged moment unfolds atop a haystack. Bull departs abruptly, leaving Sarah to struggle as she tries to descend, eventually managing a brief, precarious stand before she collapses again, a stark reminder of the fragility that threads through the island’s life.
Back at Daniel’s house, Iona finally presses Elisabeth for honesty about the past, and Elisabeth openly confronts Iona about the affair with Daniel and the secrecy surrounding Bull’s true paternity. The two women begin to rebuild a sisterly bond, even as the police, called by Matthew, interrupt their fragile moment of reconciliation. Iona slips away to find Bull, racing against a clock filled with grief and unanswered questions.
The pursuit ends in tragedy: Bull, overwhelmed by guilt and the impossibility of forgiveness, climbs to the edge and leaps from a cliff into the sea below. Iona finds her son’s body on the beach, and the sight of him cradled in her arms seals a devastating ending to a journey rooted in love, betrayal, and the heavy cost of secrets.
