Redemption: Part 1 (S06E01)

In this sixth season premiere, Jonas (Corin Nemec), unable to return to Kelowna, is eager to "finish what the missing Dr. Jackson started." He and O'Neill (Richard Dean Anderson) are introduced to the X-302, the first human-built spacecraft capable of interstellar travel. Meanwhile, the Stargate mysteriously malfunctions and Carter (Amanda Tapping) informs O'Neill that it could explode and destroy all life on Earth. "Redemption - Part 1" ends with the fate of Earth in SG-1's hands and no apparent way to avert the impending catastrophe. (Metro-Goldwyn-Mayer (MGM))