Mackenzie "Mack" Phillips suffered physical and emotional abuse as a child at the hands of his drunken father. He witnessed similar abuse of his mother as well. There is the implication that as a 13-year-old boy he planned to poison his father with strychnine, although it is never made clear whether he proceeded with this or how it was resolved. A lack of any subsequent guilt ascribed to it suggests that it was not carried out. As an adult he has a fulfilling life with his wife, Nan, and their three children -- Kate, Josh and Missy. Mack's life is shattered, however, when their youngest child Missy disappears during a camping trip while he is saving Kate and Josh during a canoeing accident. The police determine Missy is the victim of a serial killer after finding her torn dress and blood in a vacant cabin. Kate blames herself for Missy's death because of her own reckless behavior in causing the canoe accident in the first place. The tragedy derails Mack's faith and life until the onset of winter when he receives an unstamped, typewritten note in his mailbox. The surrounding snow is devoid of any incriminating tracks. The message is signed "Papa" (which was Nan's nickname for God) and invites him to meet at the cabin.