Alex and Pauline, a young couple madly in love, have just moved to the south. The young philosophy teacher and her anthropologist husband are warmly welcomed by their neighbours, Mathilde and Pierre, who are delighted to have them nearby. Until now, there was only Gilles Vasseur, a retired forestry engineer, a loner obsessed with his garden and his plants.
The man arouses an unhealthy curiosity in Pauline. Alex and Pauline's life is turned upside down the day Gilles gives Pauline, who shares his passion for botany, an exotic plant
with fascinating and disturbing properties that will jeopardise their happiness...