The meteoric rise and stunning collapse of Enron caused many to question why the watchdog system that was supposed to protect investors failed to sound any alarms about the company's dubious financial underpinnings. But Enron and its auditor, Arthur Andersen, are the tip of the iceberg. In the late 1990s, Enron was just one of the more than 400 corporations forced to dramatically restate their value because of accounting lapses, failures, or fraud. What went wrong? Through interviews with SEC officials, corporate executives, members of Congress, and investor advocates, FRONTLINE examines an oversight system gone soft and explores how market deregulation and conflicts of interest between accountants and the companies they were auditing eroded the system of controls designed to protect stockholders from investment fraud.