In a highly eclectic approach to medieval history, the prolific Sinclair (Spiegel, 1987, etc.) explores links between his ancestors—the St. Clairs—and the Knights Templar; a European presence in North America a century before Columbus; and a stone chapel in Scotland holding the key to an arcane, richly symbolic worldview. Using the carvings on a single tombstone inside Rosslyn Chapel near Edinburgh as his point of entry, Sinclair ranges widely, if erratically, in his investigation: to the history of the Templars, their position in the Holy Land, and their swift fall from power and glory; to the intricacies of the Grail legend and contemporary perceptions of the natural world; and to the exploits of his distant forebears, especially the Earls of Orkney. Henry, the first St. Clair to hold that title, not only became a master of the sea with the aid of the Venetian shipbuilding/navigating brothers Zen, but he also embarked on a famous late-14th-century voyage, with strong evidence of his having landed at both Cape Breton and Rhode Island and establishing peaceful settlements there. Henry's death upon returning home ended the quest for a Templar refuge, but his grandson William, the last St. Clair Earl of Orkney, kept Templar beliefs alive by erecting Rosslyn Chapel. Built meticulously over a period of decades, it was revered as a Grail chapel, a mecca for Templars and Masons alike since the symbols found within were common to both groups—and it remains honored today. Sinclair wallows in family genealogy and overly dense detail, but his vast knowledge and clever detective work do create a colorful, tantalizing study of the Templars and the St. Clairs—one sure to interest any serious student of the Middle Ages. (Thirty- two pages of b&w photographs—not seen.)