 Johnson realized after reading the script for the pilot episode that his character was not going to be around for the entirety of the series . This became even clearer when his character 's storylines began to develop quickly . While filming " Obscura " , Johnson was informed that his character would not be returning as a series regular for season two . Initially fearing that he had made some mistake and that they were going to kill his character off , Johnson learned that Whitney would be enlisting into the Marines . The actor has expressed his pleasure in the way the writers handled Whitney 's departure , by giving the character the exit of a hero . 
