Mathias Gold, a down-and-out New Yorker, travels to Paris to liquidate a valuable apartment he inherited from his estranged father. Upon arrival, he is startled to discover that the property is a "viager"—an ancient French real estate arrangement. This means Mathias does not have full ownership until the current tenant, 92-year-old Mathilde Girard, passes away. Matilda lives with her protective daughter, Chloé, in the apartment. Mathias is further dismayed when he learns he owes them a monthly fee as part of the viager agreement.

Desperate and strapped for cash, Mathias tries various schemes to sell the apartment despite its complicated terms. However, as he gets to know Mathilde and Chloé, long-buried family secrets and personal revelations come to light. These discoveries force Mathias to reevaluate his life, his relationships, and the true value of his unexpected inheritance. His initial intent to rid himself of an inconvenient burden gradually transforms as he navigates these emotionally complex interactions and the unseen bond he shares with the inhabitants of the apartment.