Callister Raynes was an A.I. robot that Nathan Stark had created to see if such a construct could interact with humans and be treated like a human. He had begun a romantic relationship with Jo Lupo and worked as an assistant to Nathan. Nathan had burnt down his office to protect Callister from being discovered. However, Callister was the main suspect in the apparent arson, and after Sheriff Cobb started asking a bunch of questions that would reveal the truth, Nathan had to send Callister away.