Cassie: It was The Witness. I'm sure of it. Jones: How do you know for sure? Cassie: I could feel it. Deacon: Hold on. The Witness? Dr. Eckland: He appeared in the form of Aaron Marker, your ex. Are you sure you didn't just imagine... Cassie: It wasn't a hallucination. He chose to appear as Aaron. And no, I'm not crazy. It happened.