Anesthesiologist Carol Cassella is obviously at home in the medical world that houses her vibrant debut, "Oxygen." And it isn't until the last quarter of the book that readers realize they're looking at a finely crafted mystery, as well as a sparkling literary work.

"Oxygen" is the work of a writer who is in full command of her craft. In lesser hands, the story could have bogged in medical minutiae, but Cassella never loses sight of the fact that stories are most compelling when they are about people.