Mary Thomas, a young eighth grade teacher in a Chicago suburb, is unsettled to discover a hidden camera in the desk of one of her students. When she confronts William Roth about this violation, she discovers an intelligent, sensitive loner desperately seeking a friend. She tutors him through high school and guides him through the trials of adolescence. As their relationship depends, she teaches him to dance, and comforts him when his parents take away the only thing he ever cared about, a starving runaway dog he nurtured back to health. Despite his parent’s wishes that he attend an East Coast school, William stays close to home and graduates from Northwestern University. As he begins work at the family-run lumber yard, his obsession with Mary takes a gripping hold on his life. Mistaking her interest in him for love, William shares his plans to marry Mary with his parents on a trip to Michigan’s Upper Peninsula. When William’s parents are killed in a boating accident, William lures Mary to their luxurious cabin in a picture-perfect Northwood setting. When he asks her to marry him, she refuses, never knowing the desperate murderous steps he took to ensure their future.