“All of a Sudden” (“Soudain”) explores the ability of friendship and care to transform a world of increasing competitiveness and scarcity. Set in France, the film depicts the evolution of an experimental senior care facility run by Marie-Lou Fontaine (Virginie Efira). It guides with conversational dialogue over plot, offering some of the best writing at the 79th Cannes Film Festival.

A seemingly difficult and strict boss, Marie-Lou is introduced by criticism from the nurses and caretakers at her facility, who claim her training methods are too time-consuming and expensive, requiring a training module every four months. Her approach appears neither efficient nor effective when one caretaker quits and takes a trained nurse with her.

On her commute the next day, Marie-Lou encounters a lost, nonverbal child, Tomoki (Kodai Kurosaki). Concerned for his safety, she stays with him until two adults arrive to thank her: an actor, Goro Kiyomiya (Kyozo Nagatsuka), who is the child’s grandfather, and a theatre director, Mari Morisaki (Tao Okamoto). They invite her to watch their one-man show.

After another frustrating day of work, Marie-Lou attends the play, which centers on the power of change and making the impossible possible, citing — among other examples — the abolition of psychiatric wards. Deeply moved, she stays after to speak with Mari. In their conversation, Mari shares that she has terminal cancer, which could take her life within three weeks.

Marie-Lou, in turn, shares that she entered the senior care industry after her mother died of Alzheimer’s in a facility that treated its residents as “vegetables” and “objects.” Through this exchange, the audience comes to understand Marie-Lou’s demanding methods not as harshness, but as a necessary and meaningful push toward change. By building empathy for Marie-Lou, “All of a Sudden” successfully shifts the audience from skepticism to belief in her vision.

From here, the film follows the two women almost exclusively, mirroring the intimate structure of films like “Before Sunset” — a philosophical, robust conversation between two intelligent people in search of deeper human connection. This is one of film’s most impressive qualities: its ability to capture the rare experience of meeting a complete stranger, talking for hours, and uncovering truths never before spoken aloud.

Their conversation is wide-ranging but never aimless. Each woman moves the other to grow. Mari is a warm and open-minded character, so vividly alive through the film that the audience easily forgets she is living under the shadow of cancer — but beneath her exterior, she deeply fears what lies ahead. However, Marie-Lou encourages her to take more risks and live more fully in the time she has left.

Marie-Lou’s own transformation is even more remarkable. Once guarded and stern, she is unlocked by Mari’s warmth, which strengthens her connection with her staff and deepens her commitment to her methods. Their on-screen chemistry is so convincing that their rapid bond feels entirely earned — a quality recognized when the two leads shared the Cannes Best Actress Award.

The film’s philosophical exploration of the beauty and ephemerality of life is exceptionally well-written. Its critique of capitalism is efficient and pointed, though occasionally it feels forced — most notably in a scene where Mari delivers what amounts to a Marxist lecture to Marie-Lou, who studied social theory and clearly does not need the primer. It is a rare moment of heavy-handed dialogue in a film that otherwise embeds its ideas thoughtfully and organically.

Still, one significant flaw is its length. At 196 minutes, “All of a Sudden” is impressively never boring — there is constantly some sort of action, whether through words or movement — but it is undeniably slow. The film is beautifully crafted and poignant, but could have benefitted from a shorter runtime. It is difficult to justify any film running past three hours, and “All of a Sudden,” even with its many strengths, does not quite make it.

Even so, through its elegant construction, strong performances, and profound writing, “All of a Sudden” is a remarkable film. Its length alone keeps it from greatness — but only just.

—Staff writer Anat Goldstein can be reached at [email protected].