It's the Fourth of July in Nick Quinn's sleepy New York village when a cataclysmic terror attack kills his wife, daughter, and hundreds of his fellow townspeople. Devastated and reeling, Nick is approached by one of his oldest friends, gunshot and dying, who hands him an antique pocket watch that he claims can save them all. Nick uses the ancient watch as instructed and is shocked to find himself propelled back one hour before the mass tragedy has occurred. But there's a twist: At the top of each hour, the watch will hurl Nick back two hours to relive each hour of his day anew. A desperate backward race through his day. Limited by time, Nick works feverishly to protect his family and learn the source of the mass killing. But each time Nick travels back, he discovers new angles behind the deadly plot. Enemies become allies and friends turn to foes as he unearths layer after layer of treachery. As the hours dwindle, Nick learns that there's a bigger game afoot: a second threat even more astounding than the first, which, unless he can stop it, will destroy the global order of power as we know it.