Without Remorse (John Clark Series, Bk. 1)

John Clark, a former Navy SEAL and Vietnam veteran, is still getting over the accidental death of his wife, when he befriends a young woman with a checkered past. At the same time, the Pentagon is readying an operation to rescue a key group of prisoners in a North Vietnamese prisoner-of-war camp. One man knows the terrain around that camp better than anyone: John Clark. Clark has his own mission. The Pentagon wants him for theirs.