Dr. Marie Heaton takes great pride and pleasure in guiding her patients into the land of Nod so they can have their gallbladder out, their knee replaced or their baby delivered without pain and often even without awareness. She loves her job until the unbearable happens --- an eight-year-old girl under her care dies in surgery, despite all her best efforts. The crisis leads her to question not only her professional competence but also her personal relationships. And yet, even as she carefully documents each methodical step she took and each drug she administered, she is haunted by inconsistencies.

This first-person narrative works on many levels --- as a mystery, as an exposé of the sometimes brutal juncture of the medical and legal professions, as a family drama, and as a romance of sorts. Marie has never found time for a husband. "I never meant to dam myself off from those. I just knew they would require careful scheduling." In the aftermath of the child's death she feels more alone than ever. Taking a painful leave of absence from her duties while the investigation proceeds, Marie faces a different sort of challenge --- her aging father's demise, and the realization that if she is ever going to mend her relationship with him, now is the time. Meanwhile, new knowledge comes to light through the child's autopsy that seems to implicate Marie even further. The hospital begins to back away from her, and there is the specter of criminal charges being filed against her, on top of the malpractice suit.

Through this difficult time, Marie takes some comfort in the rejuvenation of a former love affair with Joe, another anesthesiologist on the hospital staff. As their relationship heats up, more clues trickle in about the real cause of the child's death. Marie must uncover and face some unpleasant truths to clear her name.

This novel is written with a clear, even hand, and the reader feels like a part of the heady world of high-stakes surgery. Carol Cassella, a practicing anesthesiologist herself, shows skill in giving us enough medical detail to understand the nuances of the case without overwhelming us. Marie's guilt and her desire for the mother's forgiveness are well-drawn without being overdone. It would have been easy to get maudlin here, and I applaud the author for not doing so. (I think she's a much better writer than Jodi Picoult, with whom she is compared on the cover flap.) There are some great lines here, such as "It is our job to rage against the dying of the light."

Marie is an appealing character --- smart but compassionate, needy but not blinded by her needs. In the end she saves herself with some timely medical sleuthing, although the answers come at a high personal price. All in all, OXYGEN is a great read with some juicy surprises.