“Would I Lie to You?” is the first question “Gentle Monster” asks. Sitting at her piano, Lucy (Léa Seydoux) sings the Charles & Eddie classic in a stripped-back version that feels less like a love song than a question. It is a fitting introduction to Marie Kreutzer’s unsettling drama, where trust and doubt gradually become impossible to separate.

Lucy, a French concert pianist, has moved with her husband Philip (Laurence Rupp), a filmmaker, and their young son Johnny (Malo Blanchet) from Munich to the German countryside. Their quiet new life is interrupted when police officer Elsa Kühn (Jella Haase) arrives and confiscates Philip’s digital devices. He is accused of the possession and distribution of child sexual abuse material. As Lucy tries to understand what has happened, Philip offers explanations that gradually prove to be lies, forcing her to question the person she thought she knew, and leaving her with the lingering uncertainty of whether Johnny was affected.

Philip is used to looking at the world through a camera, documenting his surroundings and his family. Now, his footage becomes impossible to look at in quite the same way. Why did he record these things? Was it innocent, or was there another intention behind it? Once suspicion enters the room, even familiar images can suddenly seem to mean something entirely different. The film finds its tension in the space between what Lucy believes, what she fears and what she can actually know.

Alongside Lucy’s story, Kreutzer follows Elsa, the investigator handling Philip’s case. At work, she deals with sexual violence and crimes against children; at home, she regularly visits her father Hermann (Sylvester Groth), who is living with dementia and behaves sexually abusively towards his caregiver. Both women find themselves confronted with abuse within relationships that are difficult to simply leave behind.

Starring Léa Seydoux, Jella Haase, Laurence Rupp, Catherine Deneuve and Malo Blanchet, “Gentle Monster” premiered at the 2026 Cannes Film Festival. A French-German-Austrian production set against the bleak scenery of the German countryside, the film explores the fragile foundations of trust and how quickly the image we have built of another person can begin to fall apart. “Gentle Monster” is in German cinemas from 17 September.