Cillian Roberts was doing work for Dr. Malcolm Tell, a molecular biologist in the norther parts of Chernarus, working with a academic exchange program. Since the outbreak, Dr. Tell has been working on a cure, using unsavory and violent methods of testing. Roberts, injured in a fire during the outbreak, has remained with Dr. Tell, reluctantly helping him with increasingly bizarre tests in the hope of a cure. While conflicted on some level about his involvement with the doctor, it seems that Cillian has entered a kind of strange madness regarding aspects of Dr. Tell's philosophy and goals in the post apocalypse. Cillian is prone to spouting esoteric philosophy in the ilk of Nietzsche and other modern gothic ideas. Cillian might just be in search of a group to bring his mentality back to reality, or perhaps he is using is intellect and somewhat "injured dog" appearance to kidnap Dr. Tell's next subject.