Natasha Leonova's beauty saved her life. Discovered starving on a freezing Moscow street by a Russian billionaire, she has lived for seven years under his protection, immersed in rarefied luxury, while he pursues his activities in a dark world that she guesses at but never sees. Her home is the world, often on one of Vladimir Stanislas's spectacular yachts manned by scores of heavily armed crew members. Natasha's job is to keep Vladimir happy, ask no questions, and be discreet. She knows her place, and the rules. She feels fortunate to be spoiled and protected, and is careful not to dwell on Vladimir's ruthlessness or the deadly circles he moves in. She experiences only his kindness and generosity and believes he will always keep her safe. She is unfailingly loyal to him in exchange.

Theo Luca is the son of a brilliant, world famous, and difficult artist, Lorenzo Luca, who left his wife and son with a fortune in artwork they refuse to sell. Lorenzo's widow, Maylis, has transformed their home in St. Paul de Vence into a celebrated restaurant decorated with her late husband's paintings, and treats it as a museum. There, on a warm June evening, Theo first encounters Natasha, the most exquisite woman he has ever seen. And there, Vladimir lays eyes on Luca's artwork. Two dangerous obsessions begin.

Theo, a gifted artist in his own right, finds himself feverishly painting Natasha's image for weeks after their first meeting. Vladimir, enraged that Lorenzo's works are not for sale, is determined to secure a painting at any price. And Natasha, who knows that she cannot afford to make even one false move, nevertheless begins to think of a world of freedom she can never experience as Vladimir's mistress. She cannot risk her safety for another man, or even a conversation with him, as Theo longs for a woman he can never have.

From Moscow to the Riviera, London, and Paris, The Mistress is a riveting tale of vast fortune, cruelty, creative genius, and daring courage, as uncompromising individuals chart a course for collision.