In his first episode, he is a Marine who escapes from a mental hospital and is suffering from PTSD. He tells the team that he has been a part of some experiment. While the team investigates, a congressman is pushing for a speedy conclusion so they can award him a medal. It turns out that he has been doping himself with steroids because he wanted to be a Marine. In his second episode, he is working for colonel bell and breaks into gibbs' house to take out mike franks' daughter in law and granddaughter. Ziva is at the house to protect the girls and recognizes Damon. Damon realizes he is working for a bad person and changes sides to help NCIS