In this episode of "Le Jour où tout a basculé" (The Day Everything Turned Upside Down), Sybille, a bored and lonely housewife, has developed the peculiar habit of spying on her neighbors across the street, much to her husband's dismay.

In part one of "Le Jour où tout a basculé: Nos bébés ont été échangés" (The Day When Everything Changed: Our Babies Were Switched at Birth), a family is in turmoil. Frédéric is very jealous of his wife Anne-Sophie and accuses her of having an affair with an old flame. Although all the evidence seems plausible, is there another explanation?

Soon after Claire and Harold move into their new Parisian apartment, strange things start to open. Their new neighbors explain that their new home may have been the scene of a murder. Claire believes it, but Harold remains skeptical. Will they be able to solve this mystery?

Claire and Harold invite their new neighbors for drinks to get acquainted and thank them for their help. As the evening unfolds, the conversation becomes strained and strange things start to happen. Claire and Harold are left with many unanswered questions.

Adèle always thought that her father was dead, until a mysterious letter from her so-called half-brother arrived in the mail. After being told repeatedly by her family that her father died in a car crash years ago, Adèle is confused and shaken by the letter.

Adèle's mother tries in vain to keep the truth from Adèle, who found out her father might not be dead after all. A surprise visit complicates things even further.

Adèle's half brother Guillaume approaches her outside her workplace and introduces himself. After a brief talk, she agrees to meet him again.

Adèle discovers the whole truth about her dad and the tragic circumstances that led to his forced disappearance. Her mother's attempts to sugarcoat the truth do little to appease her anger.

Adèle's relationship with her mother is at an all-time low. Still, she's determined to meet her father. However, her meeting with her half-brother Guillaume doesn't quite go according to plan....

Guillaume finally calls Adèle back, and they set out to look for their father in his usual haunts. Will they find him?

After a first emotional reunion with her father, Adèle comes to visit him regularly on the streets, where he lives. But a shocking phone call will disrupt her happiness.

Adèle spends a few precious hours with her father who is gravely ill. She is grateful for the connection she made during the short time she spent with him.

After the death of their dad, Adèle and Guillaume have become fast friends. Guillaume even went to visit Adèle on one of her humanitarian missions. She no longer works with her mother, but the two have repaired their relationship.

"What I want is to travel and see something else other than your face, your cabbages, your carrots, and your turnips!" Sylvette shouts at her husband René, who recently retired. She dreams of traveling; all he wants is to stay home and tend his garden. Sylvette hopes that going on a cruise together will help put things right between them.

Louise is doing all she can to rescue her grandparents' marriage. She doesn't want them to throw away the forty-two years they had together. She storms off to talk to her grandmother, having had no luck with her grandfather.