Season 4 Episode 9 - Scorched Earth

Thanks to SG-1, a civilization known as the Enkarans have been transplanted from a Goa'uld slave planet to a safer, more hospitable world. But soon after they settle in, problems arise. One of their villages is attacked by a mysterious ship. The Enkarans seem to be facing a threat even more formidable than the Goa'uld. But when SG-1 investigates, they discover that the mystery ship has no hostile intent. It is merely terraforming the planet in order to make it habitable for the Gadmeer, a long-dormant alien species. Lotan, a bio-mechanical liaison created by the ship, explains that once the terraforming procedure has begun, it cannot be halted. To do so would mean extinction for the Gadmeer. On the other hand, a completion of the terraforming process would mean certain death for the Enkarans. SG-1 must find a solution to this ethical dilemma, or face the extinction of an entire race.