1939: Simon Le Tescou is a cruel and tyrannical man. For his 70 years, this rich Breton businessman, decided to reunite his whole family. Edward, his eldest son, who lives at the castle with his wife Edith and dares not stand up to his father. Antonin, the youngest, a deputy on the verge of ruin, whose new fiancée, Madeleine, unexpectedly invites herself. Victor, the youngest, an Olympic champion who accepted Simon's invitation for the sole purpose of settling accounts with his father, whom he has not seen for years. Inès, his granddaughter from Spain, whom everyone did not know existed. And a friend of the family, Eloi, a young African doctor whose research is funded by Simon. But on the night of his birthday, while he refused to feast with his guests, Simon Le Tescou is savagely murdered in his double-locked room.

Commissioner Larosière, a brilliant criminologist, and a young novice inspector, Emile Lampion, are in charge of the investigation. Under the fire of questions from Larosière, each other's alibis fall one by one and the police arrive at the conclusion that all could have killed Simon Le Tescou. While Edith and Victor fall back into each other's arms as in their youth, Louise tells Antonin, her lover, that she is carrying her child. He is overjoyed but Madeleine, who overheard their conversation, does not hear it that way.

Following her fall, Louise lost her baby; as for Madame Dupré, who narrowly escaped death, she remains paralyzed and mute. Larosière and Emile decide to settle in the castle to set a trap for the murderer. The night of the ambush, Alix narrowly escapes an assassination attempt...

Despite Eloi's efforts, Edouard succumbs to his injuries. Meanwhile, Commissioner Larosière, who is recovering from his injury in hospital, summons Inès. He is determined to make him confess the murders of Simon Le Tescou and Madame Dupré.

Les meurtres ABC (based on The ABC Murders)—As a serial killer taunts Larosière, the great detective’s career could be the next casualty.

Am stram gram (based on Ordeal by Innocence)—After the death of a beloved philanthropist, suspicion falls on her brood of adopted children.

After Inspector Lampion is injured during a police raid, Superintendent Larosière rents a cottage in a small village and begins receiving threatening letters. Based on the Miss Marple novel "The Poisoned Pen". Directed by Eric Woreth, 2009.

La maison du péril (based on Peril at End House)—When a beautiful heiress is targeted for murder, Larosière loses his heart—and nearly his life.

Le chat et les souris (based on Cat Among the Pigeons)—While investigating murder at a fancy boarding school, Larosière is haunted by his past.

Je ne suis pas coupable (based on Sad Cypress)—When death stalks a women’s retreat, a reluctant Lampion goes undercover.

Feeling underappreciated, Lampion leaves his post to a join a private investigation firm, and gets a lead on a 15-year-old case. Based on the Hercule Poirot novel. Directed by Eric Woreth, 2010.

Superintendent Larosière runs into his former captain from the Great War, who invites him to his family castle for a big announcement. Based on the Hercule Poirot novel Taken at the Flood. Directed by Eric Woreth, 2011. Aired on MHz as "The Ebb and the Flow".

Un cadavre sur l’oreiller (based on The Body in the Library)—With Larosière accused of strangling a prostitute, Lampion tries to clear his name.

Lampion befriends a young woman who suffers from terrifying visions of a bloody woman. Based on the Miss Marple novel. Directed by Eric Woreth, 2011.

Superintendent Larosière and Inspector Lampion investigate the murder of a woman last seen entering a theater. Based on the Hercule Poirot novel Lord Edgeware Dies. Directed by Renaud Bertrand, 2012.

To conclude this season and celebrate the ten years of the cult series, Blandine Bellavoir offers a special gift to the five million faithful viewers, all ages: a guided tour on the set of this season. The opportunity to return to ten years of scenaristic and visual discoveries, cult scenes and human complicity.

1:15 p.m. on Saturday was invited behind the scenes of a successful series: "The Little Murders" by Agatha Christie, whose new season will begin on January 29 on France 2 and France.tv. The detective series has not only changed heroes but also times for a leap into the 70s, colorful, unbridled and which gives pride of place to feminism ...

Through a collection of interviews and an immersion of several weeks on film sets in the North of France, Thibault Pomares tells the great story of the cult series "The Little Murders of Agatha Christie". On the programme, twelve years of time travel with testimonies from the creators, directors, set designers, costume designers and leading actors of the series (Samuel Labarthe, Blandine Bellavoir, Élodie Frenck, Antoine Duléry, Marius Colucci, Émilie Gavois-Khan, Arthur Dupont, etc.).