A sheltered young woman sustains an idealized devotion to a distant cousin she has known only through letters and a treasured miniature, inhabiting a private world of fancy that comforts her loneliness. After the death of her guardian she goes to live with a wealthy relative but keeps retreating into solitary visions of the imagined beloved. A polished yet mocking acquaintance of the cousin arrives, studies her habits, and deliberately tests and undermines her reveries by producing the miniature and treating her attachment as a game. His intrusion and scorn begin to erode the border between her dreamlike love and unsettling reality.