from the back cover:

The Duke of Avon Had Gone Missing and It Was Up To Devon to Find Him

Colonel Devon Burke knew little of the alien world in which he traveled. Yet he was determined to find the man to whom he owed his life, or else die trying. And the mysterious Julie de Valme seemed his only hope for success.

Once the toast of Paris, Julie's life had been destroyed the night of her father's death. Now she lived by her wits in a dangerous underground existence. And the one man whom she had come to trust was blind to the woman beneath the protective guise.