"A queen, a castle, a dark and ageless threat--all await Mary Russell and Sherlock Holmes in this chilling new adventure. The queen is Marie of Roumania: the doubly royal granddaughter to Victoria, Empress of the British Empire, and Alexander II, Tsar of Russia. A famous beauty who was married at seventeen into Roumania's young dynasty, Marie had beguiled the Paris Peace Conference into returning her adopted country's long-lost provinces, single-handedly...

"Mary Russell and Sherlock Holmes turn the Riviera upside-down to crack their most captivating case yet ... It's summertime on the Riviera, where the Jazz Age is busily reinventing the holiday delights of warm days on golden sand and cool nights on terraces and dance floors. Just up the coast lies a more traditional pleasure ground: Monte Carlo, where fortunes are won, lost, stolen, and hidden away. So when Mary Russell and Sherlock Holmes happen...

The shadows of war are drawing over the ancient city of Fez, and Holmes badly wants the wisdom and courage of his wife, whom he's learned, to his horror, has gone missing. As Holmes searches for her, and Russell, suffering a temporary memory loss, searches for her"self," each tries to crack deadly parallel puzzles before it's too late for them, for Africa, and for the peace of Europe.