Inspector Agnes Luthi, a Swiss-American police officer in Lausanne, Switzerland, has just transferred to the Violent Crimes unit from Financial Crimes to try to shed all reminders of her old life following her husband's death. Now, on the eve of the worst blizzard Lausanne has seen in centuries, Agnes has been called to investigate her very first homicide case. On the lawn of the grand Chateau Vallotton at the edge of Lac Leman, a young woman has been found stabbed to death. The woman, an appraiser for a London auction house, had been taking inventory at the chateau, a medieval fortress dripping in priceless works of art and historical treasures. Agnes finds it difficult to draw answers out of anyone-the tight-lipped Swiss family living in the chateau, the servants who have been loyal to the family for generations, the aging WWII survivor who lives in the neighbouring mansion, even the American history student studying at the Vallotton chateau's library. As the storm rages on, roads become impassible, the power goes out around Lausanne, and Agnes finds herself trapped in the candlelit halls of the chateau with all the players of the mystery, out of her depth in her first murder case and still struggling to stay afloat after the death of her husband.