Behind the fame of big-time sports lies a complex web of controversy and deceit. Doping–the use of banned performance-enhancing drugs (PEDs) to gain a competitive athletic edge–is common in many sports. While doping can improve performance, it poses huge risks for athletes’ health and careers. Some of the world’s top athletes, from cyclist Lance Armstrong to professional baseball player Alex Rodriguez, have seen their images tarnished by doping scandals. Still, the pressure to win and high financial stakes drive many athletes to PEDs. Award-winning author Stephanie Sammartino McPherson uncovers the shadowy world of athletes who dope, the people and organizations that help them, and the scientists and officials committed to stopping them.