As Oscar Wilde once observed, "America had been discovered before, but it has always been hushed up." This intriguing premise is one that Waldo explores in depth. While she was researching her bestselling novel Sacajawea, she came across information concerning a tribe of fair-haired, Welsh-speaking people in the Dakotas who were encountered by Lewis and Clark. From here, she was led to the legend of a Welshman named Madoc who sailed to America three centuries before Columbus; this prompted her to write Circle of Stones. Now she continues the story of Madoc's early days among the Druids during the 12th century, as well as of the extraordinary seafaring exploits that made him legendary. His story here is intertwined with that of Cougar, a Native American girl of the Calusa tribe (in the area now known as Florida). Both Madoc and Cougar are raised by people other than their birth parents, making this a tale of two foundlings. Madoc's people believe him to have been destined by the gods to lead the Druids, while some in Cougar's tribe fear she might be a shape-shifter. The novel charts their individual trials and adventures as life sets them on a course that will ultimately lead to their meeting. Despite being set in a different time period, at times Waldo's epic of discovery impresses as being part Jean Auel and part Homer. Scrupulously researched, with enlightening epigraphs opening each of the 24 chapters, Waldo's latest will satisfy fans of her previous work and prove that she has not lost her historical touch. Agent, Jean Naggar. (Aug.)