Theo meets Ria in 1939, at summer camp on Cape Cod. One day Ria finds an historic bronze medallion given by English settlers to the Indians who helped them. She gives it to Theo's friend Casco, a hermit who lives in a wigwam in the woods. Casco has run away from civilization to live like his ancestors, the Indian tribe who once occupied the area. When Theo finds Casco dead, apparently murdered, and the medallion missing, he buries his friend there in the woods, then hides in the wigwam, trying to piece together what happened.  The mystery of Casco's death becomes the enduring theme of Theo and Ria's friendship as the years go by. Searching for Casco's murderer leads them through the Cape's Indian and Pilgrim past, into the world of art and antiquities, and ultimately to some shocking revelations.