Michael Thompson had no idea that his camping trip to Dark Hollow Falls would be his worst and last day on earth or that his teenage daughter, Sydney, would be gravely wounded and orphaned in the same savage attack. Sydney’s ultimate betrayal occurred at the one place she believed was her sanctuary. When that realization coalesced with the certainty her father was dead, Sydney’s only wish was to linger in her semi-conscious state until she could die. Psychologist and FBI agent Shawn Cleary begins her investigation without knowing that the man who will become the Park Slasher is still a threat to the youngster. As she patiently works to establish a relationship with the wounded girl, more National Park attacks occur. Shawn pursues evidence and a confusing trail through the grandeur of the Smoky Mountains and the majesty of Yosemite. Still hospitalized at D.C. General, Sydney’s slow recovery is hampered by a maniacal child psychologist and a custody fight that could cause the FBI agent to cross an ethical line. A second attempt to kill the beleaguered teenager further buries her memory of the events at Dark Hollow Falls. Shawn’s developing relationship with Sydney enables her to probe the girl’s mind leading the FBI to the San Francisco home of the misguided killer. Agents sift through false clues until a startling discovery in California sends Shawn and her team to Glacier National Park with the knowledge that the attacks are more personal than the FBI could have believed. Amid blizzard conditions, Shawn leads her wary team to the treacherous, snow covered trails of Glacier for a stunning confrontation that will allow Shawn to either capture the Park Slasher and his cohorts or allow them to escape forever.