"Specific Gravity" is a fun, interesting medical mystery with a variety of puzzles for the protagonists to solve. It is also the story of a man's redemption from his past misdoings, and how he finds happiness with someone that is more than a match for him.
The book is also a philosophical reflection on the impact that medical errors make in the medical field--something that we all need to think long and hard on. With the right tools and education, hospitals have made great strides in minimizing this important problem.