Dr. Sean Nolan had never entertained the idea of becoming a part-time medical detective. His first venture had been an accidental inquiry. When the cancer deaths in his small-town practice began to rise, even claiming his own wife, he wanted to know why, and who was responsible. With no rule other than to find the truth, his unorthodox approach, occasionally stretching legal boundaries, proved an unstoppable force that left no unanswered questions.

His second investigative foray is no accident. Forty-seven people are dead in California from an outbreak of Legionnaires' disease. The Center for Disease Control has not been able to locate the source. With the outbreak fading, they have been reassigned, but the CDC director has asked Dr. Nolan to take a second look. He has been given two weeks to find the key piece of evidence.

Utilizing his own unique methods, and an unlikely group of associates, the door he unlocks is not to a single mystery, but a complex web of secrets that affect thousands of lives. Unlocking the door is simple. Forcing it open is something quite different.