In Lisbon in 1904, a young man named Toms discovers an old journal. It hints at the existence of an extraordinary artifact that--if he can find it--would redefine history. Traveling in one of Europe's earliest automobiles, he sets out in search of this strange treasure. Thirty-five years later, a Portuguese pathologist devoted to the murder mysteries of Agatha Christie finds himself at the center of a mystery of his own and drawn into the consequences of Toms's quest. Fifty years on, a Canadian senator takes refuge in his ancestral village in northern Portugal, grieving the loss of his beloved wife. But he arrives with an unusual companion: a chimpanzee. And there the century-old quest will come to an unexpected conclusion.