Derek is Ruth's brother who was first seen entering the monastery where Desmond works, while Desmond is packaging wine. He walks right up to Desmond and punches him in the face. He then apologizes to Brother Campbell before leaving. Desmond later visits Derek's house, and it is discovered that he is the brother of Ruth, Desmond's jilted former fiancée. He is reluctant to allow Desmond in, but is interrupted by Ruth, who invites Desmond in. ("Catch-22")
- The name Derek (originally Theodoric) is of English and Old German origin. It means "ruler of the people". 
- During casting for "Catch-22", he was described as "Kenneth. 20's, Male, Caucasian, Scottish. Kenneth is a working class type who is quite quick to throw a punch."