We meet Veronica Callahan, a very smart nurse who returns to Mercy Hospital after a year long tour of service in the Army. She's not afraid to take risks in order to save her patients, but this attitude might just cost her her job. In her personal life she's trying to make her marriage work with her high school sweetheart Mike, but when she sees the hospital new doctor it might not be that simple. Meanwhile, we meet Veronica's best friend and also nurse colleague Sonia, who thinks she finally found the man of her life and also Chloe, a rookie nurse who is learning the hard way how to be a nurse.