Police find a desiccated corpse on a desert road outside Las Vegas, Nevada, the seventh victim of a bizarre serial killer. Detective John Sheppard, called in to assist, is baffled by these murders. Then a clue, traces of radiation found on the bodies, leads him to a strange looking man with super human attributes who easily evades capture. Some time later, Sheppard is detained and driven to Area 51. There he meets Dr. Rodney McKay who reveals that the suspect is, in fact, an alien - a wraith - who feeds on human energy. What's more, McKay and his team have traveled to Earth from the Pegasus Galaxy, by way of a stargate, to prevent this wraith from compromising the security of the planet. But so far, Sheppard is the only one who's been able to get close to him.