When her mother died two years earlier, Izzy thought the world would change in some identifiable way, but it didn't. It didn't even slow down. Along with constantly watching her brother, Jason, to ensure he didn't repeat his involvement with drugs, Izzy has managed to get through school and the rest of her life using her mother's endless "rules" as guidance, even making up some of her own as she goes along. When her father starts dating again and then decides to get married, Izzy is unprepared. She is convinced she will hate this intruder in her ordered life and is certain that their family is complete as it is. When her father's new girlfriend becomes pregnant, and her health is threatened, Izzy finds that there might just be room in her family for Anne. And while trying to save her brother and stay true to the "rules," Izzy realizes that family involves more than blood and that rules aren't always absolute.