John Sheppard

Lieutenant Colonel John Sheppard, USAF is a fictional character in the 2004 Canadian-American military science fiction television series Stargate Atlantis, which chronicles a civilian operation exploring the Pegasus Galaxy via a network of alien transportation devices. Portrayed by Joe Flanigan, Sheppard holds the military rank of lieutenant colonel in the series and is the second-in-command of the Atlantis Expedition following the death of Marshall Sumner (Robert Patrick) in "Rising". Sheppard and Rodney McKay (David Hewlett) are the only characters to appear in all one hundred episodes of the series. Role in Stargate Atlantis Character arc John Sheppard was an experienced and a talented US Air Force Officer in Afghanistan, though his reputation was somewhat tarnished when he disobeyed a direct order in an unsuccessful attempt to save the lives of several US servicemen. When called upon to transport Brigadier General Jack O'Neill to the research base that had been established at the nearby Ancient defense facility, he inadvertently discovered that he not only had the ATA gene (the genetic factor necessary to activate Ancient technology), but that he was naturally proficient at using it. After some doubts, he finally joined the expedition to Atlantis, although Colonel Marshall Sumner made it clear he was not pleased about Sheppard's involvement in the mission.