What does Harper Cole do for a living? What has he done in the past? What prompted that career? What ended it?

What does Drewe do for a living? How does that eventually help in their pursuit of the killer?

Who do police think the killer is? Why? How is he eventually identified?

Describe Berkmann's birth and childhood. How did this shape him into the adult he became?

What is the secret between Harper and Erin? What prompts Erin to decide to tell Patrick? What does she demand of Harper? What happens? What is it that they agree on? How is the secret revealed to Drewe? To Patrick?

How do both Miles and Dr. Lenz propose to catch the killer? How are their methods similar? Different? Why is Lenz not successful? Why is Miles' method successful?

Describe the relationship between the killer and Kali...