The Four Feathers by A.E.W. Mason

Ethne had thought to escape quite unobserved; but Mrs. Adair was sitting upon the terrace in the shadow of the house and not very far from the open window of the drawing-room. She saw Ethne lightly cross the terrace and run down the steps into the garden, and she wondered at the precipitancy of her movements. Ethne seemed to be taking flight, and in a sort of desperation. The incident was singular, and remarkably singular to Mrs. Adair, who from the angle in which she sat commanded a view of that open window through which the moonlight shone. She had seen Ethne turn out the lamp, and the swift change in the room from light to dark, with its suggestion of secrecy and the private talk of lovers, had been a torture to her. But she had not fled from the torture.

She had sat listening, and the music as it floated out upon the garden with its thrill of happiness, its accent of yearning, and the low, hushed conversation which followed upon its cessation in that darkened room, had struck upon a chord of imagination in Mrs. Adair and had kindled her jealousy into a scorching flame. Then suddenly Ethne had taken flight.