Kelly O’Sullivan and Alex Thompson deliver a finely tuned portrait of adolescence, grief and unlikely bonds in 'Mouse,' a film that premiered at Berlinale 2026 and marks their most accomplished collaboration yet.
Kelly O’Sullivan and Alex Thompson’s new film Mouse slipped into the 2026 Berlin Film Festival with the quiet confidence of a work that knows exactly what it wants to say. Set in the early summer of 2002, it follows Minnie, a reserved high-school junior whose life is upended when a longstanding friendship suddenly fractures. The movie refuses melodrama; instead it builds emotional force from restrained gestures, domestic detail, and a patient, observant eye.
Katherine Mallen Kupferer carries the film with a luminous, tightly controlled performance. She rarely emotes in broad strokes; her smallest movements—the way she lingers on a kitchen table, the micro-expression that follows a failed joke—are where Minnie’s interior life is revealed. Chloe Coleman’s Callie is a clear counterpoint, magnetic and increasingly drawn to the spotlight, while Sophie Okonedo brings unexpected warmth and ballast as Helen, Callie’s mother. Iman Vellani and Tara Mallen add thoughtful, dimensional support that keeps the social world of the film feeling textured and real.
O’Sullivan’s screenplay privileges accumulation over declaration. Scenes unfurl slowly, allowing tiny shifts in behavior to compound into meaningful change. The filmmakers trust the audience to infer pasts and stakes from a look, a prop, or a clipped line of dialogue. That restraint is deliberate: long takes, measured blocking, and close framing let performances breathe without editorializing. The score is sparing and the editing favors elliptical links of mood rather than blunt scene-to-scene transitions, which keeps the film emotionally focused without feeling insular.
The period setting does more than dress the film in nostalgia. Early-2000s rituals—the neighborhood video-rental shop, mixtapes and rehearsal rooms—anchor character life in tangible routines and quiet pleasures. Production design and costumes pick out era-specific details just enough to be convincing without slipping into pastiche. Cinematography often traps Minnie in intimate, slightly cramped spaces, reinforcing how she’s reevaluating where she belongs.
What makes Mouse quietly persuasive is how domestic moments carry weight. Conversation scenes feel lived-in rather than staged; secondary characters—a guidance counselor, classmates, a barista—never shout for attention but help map Minnie’s social terrain. The film’s moral gestures are small: listening more than lecturing, presence more than tidy resolutions. A restrained exchange between Helen and Minnie, for example, functions as a compact moral fulcrum, privileging steady care over easy answers.
There are risks in this approach—the film asks for patient viewing—but the payoff is a believable, earned transformation. Where many coming-of-age stories rush to signpost growth, Mouse allows recognition to unfold slowly, so that when emotional shifts occur they feel inevitable rather than manufactured. Technically, the movie is careful: production choices are calibrated to support feeling rather than dramatize it.
Mouse confirms O’Sullivan and Thompson as filmmakers comfortable with intimacy and subtlety. Katherine Mallen Kupferer’s performance anchors a small ensemble that trusts gestures and silences to do the heavy lifting. After its Berlinale premiere the film is looking for distribution, and it should resonate with viewers who appreciate character-driven stories that reward attention.