Clay Parker is the Doctor for Fort Kohai. As the Doctor, he is responsible for curing the ailments of survivors and their injuries. During the quest Insulin, The Survivalists try to keep a steady supply of said drug for Alice Ivers, so they turn to Clay for help. They may succeed or fail in this, but throughout the events in the Sonaran Desert, Clay Parker will remain an important asset for the Survivalists and Fort Kohai alike.