The friendship between two life-long girlfriends is put to the test when one starts a family and the other falls ill.

When 12-year-old Mickey Miller moves from New York to Ireland, she soon discovers a link between herself and the 300-year-old legend of the mysterious Black Knight, who regularly haunts the sleepy Irish village. With courage and a sharp mind, she sets out to save a precious herd of white horses and to thwart the evil plans of a greedy, ambitious woman.