Tomas and Martin are a gay couple living in Paris whose marriage is thrown into crisis when Tomas impulsively begins a passionate affair with young schoolteacher Agathe. But when Martin begins an affair of his own, Tomas must confront life decisions he may be unprepared—or unwilling—to deal with.
In the heart of a city, the inhabitants of a tower wake up one morning to find that their building is shrouded in an opaque fog, obstructing doors and windows - a strange dark matter that devours anything that tries to pass through it. Trapped, the residents try to organize themselves, but to ensure their survival they gradually succumb to their most primitive instincts, until they sink into horror...