Duff McDonald's book "The Firm: The Story of McKinsey and Its Secret Influence on American Business." The book explores the history and impact of the consulting firm McKinsey & Company, examining its origins, rise to prominence, and influence on corporate America and global business. The excerpt details how McKinsey's unique approach to consulting—focusing on efficiency, strategy, and organizational structure—helped shape modern business practices, and it also scrutinizes some of the firm's more controversial decisions and projects. The excerpt also analyzes McKinsey's internal dynamics, leadership transitions, and its evolving relationship with clients, competitors, and the media.