
Sebastian, now nine years old, still accompanied by Belle, meets up with Pierre Maréchal, his biological father, owner of a stud farm in Provence. But the reunion is difficult, especially since Pierre is riddled with debt and has many other worries on his mind...
Pierre Maréchal, back home at the "Les Jonquières" stud farm, would like to tell Sylvia, his fiancée, about this unexpected son. But she's away on a trip. So he confides in old Thomas, the stable boy. Belle frightens the horses; when Thomas asks him to lead her, Sebastian wants to leave Les Jonquières...
Upon learning of Sebastian's existence, Sylvia forces Pierre to make an impossible choice: her or Sebastian. She breaks off their engagement. Back at "Les Jonquières," a despairing Pierre lashes out at everyone, especially Belle, whom he has locked up. Heartbroken, Sebastian realizes he is not well accepted...
Ordered by his father to apologize for hitting a stable boy, Sebastian is locked in a horse stall despite Thomas's pleas. César has decided to go to Canada for his grandson's wedding. Sebastian is sad, despite the support of Jeannette, his new friend...
At Sebastian's request, old Célestine arrives at "Les Jonquières" to replace the cook who resigned. Some owners are removing their horses from the stud farm. Pierre Maréchal is at his wit's end and flies into a violent rage in front of Thomas, who has come to plead Sebastian's case. Sebastian has overheard everything and has run off to the beach, where his father finds him sobbing uncontrollably...
Old Thomas teaches Sebastian to ride a horse. While walking on the beach with Belle, he meets Sylvia, who abruptly leaves him upon learning his true identity. Lambert explains to Bertrand how he can ruin Maréchal. Maréchal is forced to sell Lancelot. He is left with only Monseigneur, to whom Sebastian confides that he loves his father, even though his father doesn't understand him...
Pierre Maréchal resumes training Monseigneur. Through the notary Biard, he learns that it was Lambert who bought Lancelot. Sebastian tries to escape to join César in Canada...
Every morning, Sylvia gives Sebastian riding lessons in the woods, and he becomes an excellent rider. Bertrand, Sylvia's cousin, consumed by jealousy, asks a former stable boy from "Les Jonquières" to drug Monseigneur, who is to participate in the Prix du Marais...
Monseigneur was injured during the race; Sebastian stayed by the horse's side day and night to care for him. Pierre Maréchal sold everything he could to pay off his debts and keep "Les Jonquières," which he converted into a farm. While talking with Sylvia, Sebastian discovered that it was probably Bertrand who drugged Monseigneur...
Pierre Maréchal doesn't want to jeopardize Monseigneur's chances against Lambert's well-trained stable and refuses to enter him in the traditional July 14th gallop. He doesn't know that his son has become an excellent jockey...
After the race, it's time for the Bastille Day dance. Pierre Maréchal, following tradition, opens the ball with Sylvia. The rhythm of the waltz carries them away from the circle of dancers and they flee into a village alley, under Bertrand's furious gaze...
In Fontenelle, Bertrand and Sylvia's engagement is being celebrated. Raymond comes again to demand the promised money. Bertrand advises him not to complain because he would be accused of doping. Raymond then reveals everything to Sylvia, who runs away and goes to find Pierre Maréchal, to whom she tells how the Bishop was drugged...
Bertrand realizes his revenge is impossible and that he's been found out. He jumps in his car and flees, pursued by two motorcyclists. Running out of gas, he has to abandon his vehicle for an old clunker. But further down the road, a wrong turn sends him plunging into a ravine...