He works in the heart of a hectic ER, but his greatest fear is losing his family. Can an intrepid doctor protect his own from a twisted mind? Dr. Zack Winston's self-confidence is on shaky ground. Slated to see his young-adult daughters over Christmas for the first time in five years, the skilled emergency physician worries his relationship issues will rear their ugly heads and prevent them from bonding. His determination to focus on his personal life sinks deep when he questions a pediatrician colleague's alleged suicide attempt by drowning. Searching for the truth behind a disturbing spate of obstetrical deaths, Zack teams with the beguiling lawyer whose life he saved the previous year. As they follow a suspicious trail from the hospital morgue to the icy Potomac, he fears any misstep will plunge them into a lethal wintry doom . . . Will his refusal to stand down cost Zack everything he holds dear?