Kate devises a plan to secure her future with Malcolm by manipulating the wealthy but terminally ill Milly Theale. Her growing closeness to Milly deepens her internal conflict as she balances love, ambition, and moral compromise​.

As Milly's condition worsens, the consequences of Kate's scheme unravel. Malcolm is torn between his loyalty to Milly and his love for Kate, leading to a climactic resolution that questions the price of ambition and the nature of love.