"When the leader of North Korea is catastrophically injured, his incapacitation inadvertently triggers a 'dead-man's switch,' activating an army of sleeper agents in South Korea and precipitating a struggle for succession. Jack Ryan, Jr. is in Seoul to interview a potential addition to the Campus. But his benign trip takes a deadly turn when a wave of violence perpetrated by North Korean operatives grips South Korea's capital. A mysterious voice from...