Martin is a solitary man in his thirties, discreet and reserved. His grandfather, whose seaside home he enjoys, has just died. This year, he finds himself alone on the Vendée coast. He devotes all his time to fishing on foot, an activity he has practised since he was very young and which reassures him. Martin thrives on this little game of hide-and-seek with nature, a seemingly simple and playful pleasure. With the rhythm of the tides, Martin allows himself to be guided by his “dark passenger” towards increasingly strange behaviour and rituals.