One sunny morning the triplets disappear, leaving only a few mysterious clues behind: an open upstairs window, three missing rocking horses and some strangely shaped marks on the lawn outside. Could they be hoofprints? Used to their silly pranks, older sister Pearl sets out to find them. At the garden gate she encounters Thomas, the snooty grandson of a local earl, who warns her that the moors aren't safe today. But who is he to boss Pearl around? As she searches for the triplets and tries to outwit Thomas, Pearl's journey through the rugged Scottish hills unfolds into an incredible and perilous adventure. Pearl strives to outwit living, breathing rocking horses and several powerful land magicians, who turn the very rocks of the mountains against her. But can she trust the mysterious Thomas? And can she save her brother and sisters from the unknown fate that lies ahead? This is a tale of dark magic and destiny set in the 1920s Scottish Highlands.