Greensman
A representative of an alien race that went through drastic evolution to survive its own climate change, Klaatu comes to Earth to assess whether humanity can prevent the environmental damage they have inflicted on their own planet. When barred from speaking to the United Nations, he decides humankind shall be exterminated so the planet can survive.
Head Greensman
Ba'al travels back in time and prevents the Stargate program from being started. SG-1 must somehow restore history.
Head Greensman
SG-1 searches for an ancient weapon which could help them defeat the Ori, and discover it may be in the Ori's own home galaxy. As the Ori prepare to send ships through to the Milky Way to attack Earth, SG-1 travels to the Ori galaxy aboard the Odyssey. The International Oversight committee have their own plans and SG-1 finds themselves in a distant galaxy fighting two powerful enemies.