I am Herne

The evil influence of the fairy glance does not kill, but it throws the object into a death-like trance, in which the real body is carried off to some fairy mansion, while a log of wood, or some ugly, deformed creature is left in its place, clothed with the shadow of the stolen form. Young women, remarkable for beauty, young men, and handsome children, are the chief victims of the fairy stroke. The girls are wedded to fairy chiefs, and the young men to fairy queens; and if the mortal children do not turn out well, they are sent back, and others carried off in their place. It is sometimes possible, by the spells of a powerful fairy-man, to bring back a living being from Fairy-land. But they are never quite the same after. They have always a spirit-look, especially if they have listened to the fairy music. For the fairy music is soft and low and plaintive, with a fatal charm for mortal ears.

Lady Francesca Speranza Wilde
Ancient Legends, Mystic Charms, and Superstitions of Ireland