Provence, 1926. Scotland Yard detective Joe Sandilands is on leave, driving his way south to the Riviera while dropping off his niece at an ancient chateau.

A troubling crime committed just before their arrival leaves a clear message that more violence is to come. To allay panic, Joe agrees to stay on and root out the guilty person. But, despite Joe's vigilance, a child goes missing and an artist's beautiful young model is murdered in circumstances eerily recreating a six hundred-year-old crime of passion.

Helped and hindered by a rising star of the French Police Judiciaire, Joe must delve into a horror story from the castle's past before he can tear the mask from the diseased soul responsible for these contemporary crimes.