Sylvie, a young archaeologist, travels to France after receiving an invitation from her uncle, a renowned historian. When she arrives, she discovers that he is missing.

His disappearance appears to be connected to the recent discovery of a mysterious underground chapel from the Crusades. Sylvie must uncover how the events are linked.

She also has to find out who is trying to stop her from revealing the truth and save her uncle while uncovering the long forgotten secrets of the Knights Hospitaller order.