Dir: Lea Mysius | France 123’ 2026
Léa Mysius turns her talents to thriller mode with this disturbing that intoxicates like a slow poison. The Birthday Party is one of Cannes 2026’s most vicious surprises: a swampy, slow-burn invasion thriller that weaponises silence, isolation and family resentment.
Adapted from Laurent Mauvignier’s Histoires de la nuit, the film follows a couple (Bastien Bouillon and Hafsia Herzi) and their plucky little daughter Ida living on a remote marshland property. Mysius makes use of a series of echoing gongs to get the adrenaline pounding as preparations for a birthday dinner spiral into terror when mysterious men suddenly arrive as the uninvited guests unleashing a feast of cognitive dissonance instead of gourmet catering.
Benoît Magimel delivers another powerhouse turn as a volatile father figure whose protective instincts blur dangerously into barely controlled violence. It’s another badass performance that the actor has crafted over the years and has now made his ‘shtick’— bloated features, heavy breathing, dead eyes and explosive physicality, the addition of eye make-up and false teeth giving him a faint whiff of Ken Dodd.
The film’s emotional anchor, though, is Tawba El Gharchi as Ida, the young daughter silently watching the adults disintegrate around her. Mysius gives the teenager the film’s sharpest perspective, turning her into both witness and judge as the night descends into brutality.
Shot in bruised greys and swampy greens, The Birthday Party feels less like a conventional thriller than a waking nightmare about masculine violence and emotional decay. It occasionally disappears too deeply into atmosphere, but when it bites, it bites hard. Cannes has had louder films this year — few as suffocating.
The film is not flawless. At just under two hours, Mysius occasionally overindulges in atmosphere at the expense of momentum, and some late revelations feel more symbolic than dramatically earned. Yet even when it threatens to disappear into abstraction, The Birthday Party remains hypnotically watchable because of the intensity of its performances and the director’s refusal to dilute the story’s cruelty.
Whether this is truly a thriller at all remains debatable. The invasions, assaults and confrontations are merely the delivery system for something sadder: a portrait of emotional rot spreading through isolated lives. Mysius uses genre mechanics to expose loneliness, repression and masculine violence with almost surgical precision.
By the end, The Birthday Party leaves behind the sensation not of surviving a thriller, but of waking from a nightmare you can still physically feel in your chest. It is cold, punishing cinema — and among the most unsettling competition titles Cannes has unveiled this year.
CANNES FILM FESTIVAL | IN COMPETITION