Financier, blackmailer/conman Barney Chard is sure he's got mark Dr. Oliver McAllen right where he wants him. He knows McAllen's secret. He just needs to politely apply the right pressure. McAllen spends too much time fishing to be a threat.(Goodreads)
James Henry Schmitz (October 15, 1911 – April 18, 1981) was an American science fiction writer born in Hamburg, Germany of American parents. Schmitz wrote mostly short stories, which sold chiefly to Galaxy Science Fiction and Astounding Science-Fiction (which later became Analog Science Fiction and Fact). Gale Biography in Context called him "a craftsman-like writer who was a steady contributor to science fiction magazines for over 20 years." (Wikipedia)