It began on a Sunday. An ordinary Sunday, and a family trip to the mall. Will Carter takes his five year-old daughter to the bathroom, and there he is witness to a fatal assault on an innocent stranger. Over the next few days, Will tries to put the experience behind him, but when he sees one of the killers outside his home, he becomes more and more involved, soon passing the point of no return. Becoming drawn deeper and deeper into something he does not understand, Will feels increasingly out of his depth, and is soon asking where this is going and was the victim as innocent as he first thought...