According to Scottish legend, the kelpie, a magical sea creature, grants good fortune to the Isle of Caransay upon finding a bride on the sea rock. When Meg MacNeill spends one night on that rugged rock as local tradition demands, a handsome man emerges from the sea—and passion takes its course. Legend fulfilled, the mysterious man disappears.

Seven years later, Dougal Stewart, engineer and deep sea diver, returns to the Caransay to build a lighthouse on the very rock where he washed ashore—but Baroness Strathlin is determined to stop construction. Little does Dougal realize that the barefoot island beauty he often meets is not only the mysterious baroness herself, but the girl he once loved that memorable night—and the fair-haired boy with her is his own son.