Blackmail is not always predictable, especially if it is carried out by professionals - real masters of blackmail. But the famous detective - Miss Silver - an excellent analyst, a subtle psychologist, endowed with a good memory and natural observation - when she takes on solving crimes, she always does it brilliantly, causing respect and admiration even among skeptic cops. This exciting story begins with a shipwreck, continuing with a flurry of criminal action and daring adventures... To protect yourself from blackmail. Miss Underwood calls private detective Maude Silver for help. But the circle of extortionists is growing, murders follow one after another, the drowned lover of Miss Underwood's niece appears in the city alive and unharmed... Only a person with a razor-sharp mind and a truly sixth sense can understand this complicated story...