A massive storm system is unleashing its fury from Illinois to Florida - where it collides with a tropical disturbance and rages up the eastern seaboard. In the midst of the wind, rain and snow, Rockford Homicide Detective M.C. Riggio, FBI profiler Maggie O'Dell, and Nashville Homicide Lieutenant Taylor Jackson find themselves fighting not just the elements, but three diabolical killers ...Rockford, Illinois - A young co-ed's body is pulled from the Rock River, and Violent Crimes Bureau Detective Mary Catherine 'M.C.' Riggio and her partner, Kitt Lundgren, quickly learn that things are not always as they appear at first glance. Pensacola, Florida - FBI Agent Maggie O'Dell is about to do something she swore she'd never do again: climb into a helicopter. But a US Senator's family has gone missing aboard their houseboat, and Maggie and her partner, R.J. Tully, have been dispatched to accompany the rescue crew on their search. Soon, however, there is an even greater danger on board...Washington, D.C. - Metro Nashville Homicide Lieutenant Taylor Jackson has reluctantly agreed to take the place of her fiancé, FBI profiler John Baldwin, as a presenter at the annual Freedom Conference. But when two guests go missing, and one of them is found dead in his room, Taylor discovers an assassin amongst the spies - one with a deadly score to settle.