When the team travels to a planet ruled by the Goa'uld Cronos, they are surprised that they are already known by the people there. We soon learn the SG-1 team is not what they appear to be. They are in fact the robot replacements created by Harlan. Now the real SG-1 team must try to rescue their counterparts, and correct an earlier error they were responsible for.

Episode Viewers and Ratings

Season 4 Episode 21 of Stargate SG-1 resulted in a 0.00 rating in the 18-49 demographic.

Stargate SG-1 Season 4 Episodes...

• s04e01 - Small Victories (2)
• s04e02 - The Other Side
• s04e03 - Upgrades
• s04e04 - Crossroads
• s04e05 - Divide and Conquer
• s04e06 - Window of Opportunity
• s04e07 - Watergate
• s04e08 - The First Ones
• s04e09 - Scorched Earth
• s04e10 - Beneath the Surface
• s04e11 - Point of No Return
• s04e12 - Tangent
• s04e13 - The Curse
• s04e14 - The Serpent's Venom
• s04e15 - Chain Reaction
• s04e16 - 2010
• s04e17 - Absolute Power
• s04e18 - The Light
• s04e19 - Prodigy
• s04e20 - Entity
• s04e21 - Double Jeopardy
• s04e22 - Exodus (1)

Stargate SG-1 Show Summary

Step through the Stargate with SG-1, a team of soldiers and scientists, as they travel instantaneously to other planets to explore, forge alliances, defuse crises, establish trade, investigate ancient mysteries and defend Earth from such hostile forces as the Goa'uld and the Replicators.

For eight years, from their base at the U.S. Air Force's Stargate Command in the Rocky Mountains, Colonel Jack O'Neill, Dr. Daniel Jackson, Lt. Colonel Samantha Carter and alien warrior Teal'c have braved everything that the universe has thrown at them, from interstellar war and evil twins to passing and ascension.

But changes came to SG-1 as it began its ninth year of fearless service to Earth. New faces joined the team, as Lt. Col. Cameron Mitchell tries to fill the very big shoes of former SG-1 leader O'Neill, while General Hank Landry must adapt to the unique challenges of running Stargate Command, a posting unlike any other the military has to offer.

Offworld, SG-1 might have new friends - or new foes - in Vala, a former Goa'uld host turned freedom-fighter; and Gerak, a Jaffa leader who vies with Teal'c for political control of the new Jaffa nation.