This story is set in Tom Clancy's Jack Ryan series. By the chronology of that series it is the first book, but should NOT be read first. In order to appreciate its finer points, readers should be familiar with CIA operative John Clark and his behind-the-scenes role. This is John Clark's backstory.
John Clark was once John Kelly, a Navy SEAL and Vietnam veteran. He sails, dives and enjoys life. When his girlfriend is killed by drug dealers, John is devastated. His anguish turns to rage as he learns about the trafficking in drugs and human lives in his city, unnoticed by John and almost everyone else. He puts his combat skills back to work as he stalks and kills violent criminals. He also begins working for the Federal government on very similar missions. It becomes increasingly likely that his two lives will collide.
This is an excellent book which explains much about the skills, attitudes and loyalties John Clark demonstrates throughout the Jack Ryan series. Several familiar faces appear briefly in the story, making intriguing connections. Well-read Tom Clancy fans will enjoy these revelations, but they are not necessary to follow the story. The story itself is a good one, but has some very disturbing events and implications. Not for the squeamish.