Underground

S1, E8: With the city's food supply dwindling the Stargate Atlantis team must search for an alternate food source. The team begins negotiation with a simple group of farmers known as the Genii. Untrusting of outsiders the Genii are hesitant to any sort of trading--until Major Sheppard (Joe Flanigan) demonstrates the team's advanced weaponry. A deal is struck to exchange food for explosives. But upon returning to the Genii village to make the exchange they stumble upon technology that leads them to believe the Genii are not at all what they seem.