A young mother is recuperating in a San Francisco hospital when she suddenly struggles for breath. The hospital's doctors are mystified by her death. How did this happen? Then similar cases appear. Just as patients are about to be released ,they become devastatingly sick. As Lieutenant Lindsay Boxer and the Women's murder club probe deeper into the incidents, they wonder if these cases are coincidences. Or is a maniac playing God? When someone close to the Club exhibits the same symptoms, Lindsay fears no one is safe.