Lt. Col. Mitchell is a gifted fighter pilot and was injured flying the experimental X-302s while flying cover with the Earth fleet, protecting SG1. After recuperation, Jack O'Neil handpicked Mitchell to lead SG1 in his absence. Mitchell jumped at the chance. After reassembling the wayward members of SG1 he led the team in search of new technology and civilizations to help against the new Ori threat. During his stay with one such Civilization, he learned the powerful and deadly Sodan martial arts. The team learned that Mitchell was the right replacement for Jack, and warmed up to him quickly.