The corpse of a man dressed as a Templar is found one morning at the foot of the wall of the Constanza Tower of Aigues-Mortes. Everything seems to indicate that his death was an unfortunate accident, but a closer examination reveals that he was killed. Soler and Marchal discover that the victim is Marco Salieri, a guide of the tourist office of the city to which his friends had prepared a bachelor party set in the Middle Ages. Marco promised with Charlotte the daughter of Olivier Rohan, a well-known professor of medieval history seemed about to discover a mythical Templar treasure. Was he killed for this reason? Soler and Marchal will discover then that Marco Salieri is not what he appears to be.
