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.

Sybille is concerned that the man she's been spying on is now watching her. Undaunted, she walks across to his apartment building to investigate. But she is stopped in her tracks, and things don't go according to plan.

Sybille's anxiety escalates as the spying continues. The stranger across the street is staring out the window all day long. To make matters worse, her husband comes home late, very late, and is less than sympathetic to her plight...

Sybille and Édouard are still at odds with each other as Sybille now accuses him point-blank of having an affair with Vanessa. The mysterious neighbor doesn't cooperate with Édouard's scheming but pursues her own agenda.

Sybille and Édouard meet for drinks at Vanessa's apartment. Vanessa finally admits that a tenant lives with her, but he remains elusive. Vanessa's dubious explanations do not satisfy Sybille and only add to her curiosity.

Sybille finally finds an opportunity to knock on the door of the stranger who has been spying on her for weeks. She braces herself and confronts the stranger.... Or is he a stranger? A pleasant surprise is in store for her.

Édouard's life is starting to unravel as the awful truth comes out. Benoît makes some startling revelations to Sybille, but she is not entirely surprised. It's not all gloom and doom for her, however, as an old flame is rekindled between them...

Vanessa is coming over to Sybille's house, which is now Benoît's as well. They don't need to spy on each other anymore, but Vanessa is bringing her binoculars anyway. As for Édouard... justice has prevailed.