When Countess Zorah Rostova sweeps into the office of London barrister Sir Oliver Rathbone and asks him to defend her against a serious charge of slander, he is astonished to find himself accepting. For, from what he learns of the case, a defense of the countess can only earn him notoriety. Twenty years earlier, Countess Zorah's countryman Prince Friedrich had abdicated his throne to marry a woman who was unacceptable as queen. Since then the prince and his beloved Princess Gisela have lived in romantic exile as the world's most famous lovers. Now the prince is dead, and Countess Zorah claims that Princess Gisela has murdered him. Unfortunately she cannot produce a shred of evidence to support her shocking assertion. Nor can that formidable private investigator William Monk. However, Monk and his friend, nurse Hester Latterly, do establish that the prince was murdered. And as events unfold, the likeliest suspect seems to be Countess Zorah herself.