Alison Barbour, scholarly author of such erudite works as "Folklore in Fact, Legend, and the Human Psyche", leads a double life. Off-duty from her academic pursuits she writes sexy thrillers as "Mariana Grange". Though kept a careful secret from everybody, Mariana brings in healthy royalty checks. With five months left of a leave of absence from teaching, and Mariana dollars in her bank account, Alison, her parents now dead, decides to go in search of her roots. Her clue is a photograph of a great-grandmother whom she closely resembles. The identification on the back reads: "Christina MacLeod. Born in 1849, at Torsaig, Isle of Lewis, Outer Hebrides, Scotland." So it's off to the Hebrides where Alison expects nothing more than relaxation, a chance to explore and to meet, perhaps, the descendants of people who might have known the red-haired Christina. But fog-shrouded, rainy Lewis has more than the mysterious Standing Stones at Callanish (distant cousins of the more famous ones at Stonehenge) to offer visitors. Evil doings have been swept in from across the sea. Before her departure from the States, Alison has been told about the "Book of St. Neacal", by a 7th-century Celtic monk. The Book, a treasure-trove of word-of-mouth histories and legends, disappeared along about the 11th century. Its monetary value is almost as extraordinary as its historical worth. More than one person is seeking the Book. The trail has led to Lewis and stirred up violence, associated and unassociated, in which Alison becomes enmeshed. The finale is as chilling a finish as Elisabeth Ogilvie has ever conjured up to tingle her readers' spines. Miss Ogilvie still lives in a remote part of the state of Maine, but since her trip to Lewis to research this book, it's clear that a part of her heart is there.