A young mother is recuperating in a San Francisco hospital when she is suddenly gasping for breath. The call button fails to bring help in time. The hospital's doctors, some of the best in the nation, are completely mystified by her death. How did this happen?

This is not the first such case at the hospital. Just as patients are about to be released with a clean bill of health, their conditions take a devastating turn for the worse.

Accompanied by the newest member of the Women's Murder Club, Yuki Castellano, Lieutenant Lindsay Boxer probes deeper into the incidents. Could these cases just be appalling coincidences? Or is a maniac playing God with people's lives? When someone close to the Women's Murder Club begins to exhibit the same frightening symptoms, Lindsay fears no one is safe.