Stargate Atlantis: Season 3, Episode 9

3 - 9: Phantoms

Major Leonard's team fails to check in with Atlantis while on a mission exploring an anomalous energy spike. Because the anomaly also makes radio transmission impossible Sheppard must assemble a team in search of the missing men. When the team arrives on the planet they're shocked to find the bodies of several Genii soldiers who have apparently killed each other.