Selkie by Brian Froud

The sea trows and selkies of Scotland are shape-shifting faerie women who leave their sealskins by lying on the shore to dance on the moonlit beaches, beguiling all men who gaze upon them. If a man gains possession of her sealskin, the faerie is trapped and cannot return to her otherworld. As faerie wives, they make good and fertile companions, yet are ever wistfully longing for their own natural form. Eventually, however, they always find their own skins again to swim freely to their own land, leaving the men sorrowing for their loss. A reminder then that faerie women cannot be imprisoned in a relationship, but must be allowed to be free to fulfill the destiny of their faerie souls. These stories, with their seemingly arbitrary prohibitions (usually physical, as in the accidental blows) tell us that as men we must truly value faerie women, treat them gently, and acknowledge their otherworldliness. Our actions or words must do no damage to their mysterious transcendence.