On a flight home after a visit to her mother, Grace finds herself seated next to Clara—her husband Oscar’s ex-wife. Initially, their interaction is nothing more than polite small talk, but it soon takes an unexpected and unsettling turn. Clara, with an unsettling calmness, begins to share details that shake Grace to her core. She reveals that she and Oscar were the ones who designed the house that Grace now calls home. She talks about how Oscar still sends her flowers and cakes on special occasions,

and how, whenever there’s a conflict in his marriage with Grace, he calls her for advice and comfort—including during their most recent argument. Each of Clara’s confessions chips away at the foundation of Grace’s understanding of her marriage. The layers of intimacy and emotional attachment between Oscar and his ex-wife begin to unravel in a way that Grace never could have imagined.