Penny Conley is still recovering from the untimely death of her husband. But she and her five-year-old daughter, Willow, seem to be thriving in their West Virginia suburb. Penny works for esteemed archeologist Simon Van Etton, who is like family to her -- even Simon's great niece, Diana, has become one of Penny's closest friends. So when a distraught Penny calls Diana late one night, Diana is the one who comes running. But just as Diana arrives, the house explodes, leaving Penny in a coma.

As Diana and Simon try to figure out what happened -- and why -- two shocking discoveries are made: First, investigators find a bomb in Penny's basement. Then, new facts about Penny's dark past come to light. Determined to find the truth about her friend, Diana keeps digging for clues. But someone is following her every move -- and is willing to kill to make sure that Penny's secrets stay dead and buried.