Lucas, a young researcher at the INRA agricultural research institute, is obsessed by the analysis of movement: that of the horses he studies in his laboratory and the movement of his own feet when tap-dancing, a hobby which lifts him out of the super-organised rut of his existence. Both his professional and his love life seem to be stalled, until the day his brother Luigi, a keen horse-breeder and small-time crook, is accidentally killed by a stallion.