A is a maverick. She lives in the Pacific Northwest. Her life involves sustainable off-grid living in the wild forest. Her neighbors more commonly found are bears, elks, mountain lions and some humans. A is an adventurer and overall international woman of mystery.
D is a is a forensic neuropsychologist who is the co-author of five previous psychological thrillers. From his understanding of the borderland between brain and mind, he brings to the table over 30 years of experience examining what makes an individual tick. He is currently a department chief at one of the oldest and most venerated psychiatric hospitals in the country and is a professor at the medical school of what some consider to be the "World’s Greatest University”.