On this edition of ST, we speak with author and journalist Kirstin Downey, whose new book, just out from Doubleday, is "Isabella: The Warrior Queen." It's an engrossing biography of Isabella of Castile, the powerful Queen of Spain who sponsored Christopher Columbus's journey to the New World, established the Spanish Inquisition, and became one of the most influential female rulers in history. As per a starred review from Kirkus: "A strong, fascinating woman, Isabella helped to usher in the modern age, and this rich, clearly written biography is a worthy chronicle of her impressive yet controversial life." And further, from BookPage: "From 'Game of Thrones' to 'Pillars of the Earth,' popular culture offers up medieval stories where royal blood grabs for power, where crucial alliances are built between church and state, where important people suddenly fall over dead after a sumptuous meal, poisoned by a hidden rival. But this world did, in fact, exist, and the subject of Kristen Downey’s new biography, Queen Isabella of Castile, maneuvered through it with unlikely and thrilling success.... Downey writes with eloquence and intensity about Isabella’s life, making what could have been a distant history into a dramatic page-turner."