Archaeological illustrator Beatrix Forster accompanies her husband, retired archaeology professor William Forster, to excavate the cemetery at San Miguel in Excelsis, an isolated medieval sanctuary in the mountains of northern Spain. Bill's former student, now a priest in Navarre, has enticed them out of comfortable retirement with the rumor that the infamous medieval knight and founder of the sanctuary, Teodosio de Goñi, may be buried at the church.
Despite initial misgivings about working in Spain under the shadow of Franco's dictatorship, they accept the project and travel to Navarre with students from the University of Toronto. Personalities clash as the students grow weary of the remote location, but when one of the students is brutally murdered, accusations begin to surface.
Beatrix and Bill fear that the local Civil Guard, much hated by the populace, has bungled the investigation, and they take it upon themselves to determine the identity of the killer. They soon find that everyone at San Miguel has something to hide, and Beatrix begins to wonder just how well she and Bill know those with whom they are living.
