|Occupation||A.I. robot, former assistant to Nathan Stark.|
|Appearances||"Right as Raynes"|
Callister Raynes was an A.I. android that Nathan Stark had created to see if such a construct could interact with humans and be treated as 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 as an AI. 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.
Right as Raynes
In the Episode "Right as Raynes", Callister returned to Eureka unexpectedly. He arrived in Café Diem, where Douglas Fargo saw and took a picture of him before running off to Nathan Stark and interrupting him during a meeting. When he interrupts him, Nathan says, "I swear to god Fargo, the world better be on fire." to which Fargo responds "Pretty close." In the café, Jo walks in to find Callister after Carter and Allison. She goes up to him and kisses him because he came back, but then punches him for leaving. She then promptly leaves the café. Callister then goes to the old lab and Nathan finds him there. He tells Nathan what is wrong and he tells Callister to stay there while he goes to get something he thinks will help. However, Callister goes to Beverly's and meets up with Zoe. Nathan finds him there and Callister ends up setting the rooms on fire by accident.
Callister and Nathan are confronted by Carter and Allison in his old workspace and Callister runs away via Nathan's car. He sees Zoe on the side of the road and picks her up, and they make it as far as the bus station before Callister is near death/shut down. After getting a phone call reporting that someone had seen Zoe and Callister, Nathan and Carter rushed to their location. Zoe brings them to where she took Callister and Nathan kneels down next to him, realizing that Callister is going to shut down and he has no way to stop it from happening. Callister reminds Nathan of something Alan Turing said; "He said he figured God could give a computer a soul if he wanted to. Do you think that's true, dad?" Nathan replied, "I know it is." Then Callister's eyes go dark, signifying that he is no longer active.