Iris, Naomi Watts, a writer and college professor in Manhattan, is grappling with the emotional fallout of her mentor and closest ally, Walter Bill Murray, taking his own life. The narrative unfolds through intimate conversations among Iris, Walter's ex-wives, and his adult daughter, gradually painting a portrait of Walter’s long, complicated career and his three troubled marriages. At the funeral, his third wife, Barbara Noma Dumezweni, pulls Iris aside with a personal request that will pull Iris deeper into Walter’s world than she ever anticipated. Barbara asks Iris to adopt Walter’s aging Great Dane, Apollo, a task Iris accepts on a provisional basis, setting in motion a cascade of responsibilities that will test Iris’s patience, her living space, and her own sense of purpose.
As the layers of Walter’s life begin to surface, the film hints at a more private, controversial backstory. Iris discovers that Walter had once been her professor and, in a difficult twist of memory and fate, they shared a casual romantic moment. The burden of his legacy weighs on Iris, especially since she had been tapped to write his biography, a project she has struggled to move forward with due to writer’s block and self-doubt. Walter, sensing her inertia, nudges the process along by introducing his daughter, Val Sarah Pidgeon, to contribute to the manuscript. In the present timeline, Iris digs into Walter’s digital life, handing his laptop to a technology professional who can recover a trove of email correspondences, hoping to uncover material that might anchor or inspire the biography.
Meanwhile, Jerry Josh Pais, Iris’s agent, pressures her to complete the project as interest in Walter’s life as a literary giant begins to surge following his death. The practical realities collide with Iris’s grief when Apollo’s sheer size and stubborn temperament turn her quiet apartment into a chaotic space. The canine companion tethers Iris to her home in ways that feel both comforting and disruptive: Apollo beds down in Iris’s space, rearranges her research materials, and earns the vigilance of the building’s superintendent, who warns of rule violations before reporting Iris to the landlords. The mounting stress threatens Iris’s housing situation as she receives eviction notices tied to Apollo’s presence.
A turn comes when Iris realizes she might leverage a legal loophole by registering Apollo as an emotional support animal. The idea becomes a catalyst for broader change: she seeks a service animal referral from her therapist, who, in addition to supporting her through the grief, invites Iris to process her pain by writing a transformative story in which she speaks directly to Walter. In this narrative exercise, Iris replaces the real struggle with an imagined, manageable proxy—a large dachshund stands in for Apollo—allowing her to confront Walter’s choice and its consequences with greater emotional distance. The exercise becomes a doorway to acknowledging the burden of the biography while reclaiming her own voice as a writer. The decision crystallizes: Iris will pause the Walter biography and pivot to a new book focused on her lived experience with him, letting Val finish what remains of the manuscript, and freeing herself to chart a fresh artistic path.
Time passes, and Val invites Iris to a new horizon: a beach house on Long Island that belongs to Walter’s family but is slated to be sold soon. Iris accepts the invitation to spend a summer there, accompanied by Apollo, whose aging process—arthritis and frailty—stirs a deeper tenderness in Iris and a renewed sense of responsibility. By this point, Val has completed Walter’s biography, granting Iris a sense of closure on that chapter, even as the dog’s presence remains a daily reminder of Walter’s influence. The house becomes both sanctuary and stage for Iris’s healing, a place where the currents of memory meet the tides of the present. One day, Iris spots Apollo lying inert on the sand and fears the worst, only to discover that he is simply at rest, enjoying a moment of quiet dignity as the sea winds circle the shore. In that breath, Iris recognizes the arc of grief—and the quiet power of choosing a new story to tell.
