He finds out when he briefly visits mum that he's got a half-sister called Fauna. He decides he wants to live out in the marshes of the delta, and Fauna runs off with him, in an incestuous fever. Some of you may have heard of the phenomenon referred to as Genetic Sexual Attraction. This is when siblings live apart until they meet at adulthood, at which point they feel an overwhelming sexual attraction for one another. So just in case anyone would feel the incestuous side of the story is unrealistic, I promise you it isn't.
Mihail and Fauna live in a shack in the delta, building a house on stilts in the middle of the lake during the daytime. This is presumably so they can get away from the copious amphibians, and the toad chorus that is their bedtime accompaniment. The toads actually may well represent the townspeople.
It's a pretty minimalistic and slow film (the credits include a thanks to Béla Tarr and Ágnes Hranitzky), with marvellous cinematography. Cinematographer Mátyás Erdély is into his abstract patterns and we see some great shots for example of timber stacks and swirling inky black water. There's also a panning shot of the delta that would make a Dutch genre painter salivate, and a funeral scene that would stir the bones of Tarkovsky. There are moments to sigh and gasp at the cinematography.
It's obvious all along that things aren't going to end well. Fauna's stepfather is jealous and the local scum have decided that Fauna and Mihail are setting themselves up above everyone else. What is beautiful, tear it down.
The film reminds me of an aphorism I heard once heard, there are two peasants, the first of whom has a cow. The second peasant is visited by God who says that he is willing to grant him one wish; the ignorant peasant's wish is that God kills his neighbour's cow.
It's not a licentious film; there is no emphasis on the incest and the sex side of things. However there are scenes that are not for the faint of heart.
Some reviewers have tried to paint a picture of this film as incomprehensible; don't be misled into believing that. There are even mystical touches to this film, there's something deep and primal and wet about the delta; I felt almost like I was waste deep in water at points. The delta is maybe about a closeness to God, or whatever secular equivalent you feel deep within. The delta is where the land crumbles away, it's fertile and gliding into an ocean. Forget it's the Danube and the Black Sea, and feel the essence, the fertility, the clarity, and the flow. At the end I was left with the raw taste of vodka and watermelon, and an intense feeling of immense communal jealousy.