President Jack Ryan deals with the worst breach U.S. intelligence has ever suffered in this "compelling and frighteningly realistic"* thriller in Tom Clancy´s #1 New York Times bestselling series. A massive data breach has compromised the personal information of millions of American military officers and intelligence agents. After several deadly attacks on off-duty personnel and their families, President Jack Ryan faces one of the greatest challenges of his career. Can he find the hackers and cap the flow of information before it´s too late?