An old man is found wandering in the Arizona desert, apparently demented, talking in rhymes. In his pocket is a diagram of a 14th century monastery in France that is being excavated by a team of archaeologists from Yale University. The head of the team disappears suddenly and three of the team members decide they will track him down. They are Kate Erickson, athletic, passionate about mediaeval architecture and rock climbing; dreamy Chris Hughes; and Andre Marek, obsessed with the mediaeval world. Altogether they possess great knowledge of the fourteenth century - or so they thought, until they find themselves in a world, which teaches them how little they really know.