O'Neill and Teal'c risk their lives to keep the Replicator bugs from gaining a foothold on Earth, while Carter helps the Asgard fend off a Replicator invasion. A warring alien race offers to exchange their advanced technology for Earth's help in defeating their enemy.

Season 4 Episode 20 - Entity

The SGC is invaded by an alien life force that takes up residence in the base computer system -- and in Major Carter. Air Date : 9th-Feb-2001

Season 4 Episode 1 - Small Victories (2)

O'Neill and Teal'c risk their lives to keep the Replicator bugs from gaining a foothold on Earth, while Carter helps the Asgard fend off a Replicator invasion. Air Date : 30th-Jun-2000  Read More

Season 4 Episode 2 - The Other Side

A warring alien race offers to exchange their advanced technology for Earth's help in defeating their enemy. Air Date : 7th-Jul-2000  Read More

Season 4 Episode 3 - Upgrades

A Tok'ra archaeologist arrives at the SGC with newly discovered technology, giving the SG-1 team superhuman powers. Air Date : 14th-Jul-2000  Read More

Season 4 Episode 4 - Crossroads

Teal'c is reunited with his lost love -- a woman who claims to have found a way to communicate with her symbiote and defeat the Goa'uld. Air Date : 21st-Jul-2000  Read More

Season 4 Episode 5 - Divide and Conquer

When a member of the SGC tries to kill a Tok'ra, it is revealed that O'Neill and Carter may be victims of an untraceable form of Goa'uld mind control. Air Date : 28th-Jul-2000  Read More

Season 4 Episode 6 - Window of Opportunity

O'Neill and Teal'c are caught in a time loop in the SGC, and must relive the same 10 hours over and over again. Air Date : 4th-Aug-2000  Read More

Season 4 Episode 7 - Watergate

The Russians recover a Stargate from the bottom of the ocean, and turn to the SGC for help when their experiments go awry. Air Date : 11th-Aug-2000  Read More

Season 4 Episode 8 - The First Ones

Dr. Jackson is taken captive by an Unas while on an archaeological dig. The SGC mounts a rescue operation, but discovers a danger of their own. Air Date : 18th-Aug-2000  Read More

Season 4 Episode 9 - Scorched Earth

SG-1 is caught in a conflict between two civilizations trying to colonize the same planet. Air Date : 25th-Aug-2000  Read More

Season 4 Episode 10 - Beneath the Surface

The members of SG-1 are used as forced labor in an underground alien facility after their memories are erased by the ruling elite. Air Date : 1st-Sep-2000  Read More

Season 4 Episode 11 - Point of No Return

SG-1 investigates a conspiracy theorist who has detailed knowledge of the Stargate program. Air Date : 8th-Sep-2000  Read More

Season 4 Episode 12 - Tangent

A test gone wrong leaves Jack and Teal'c marooned in space aboard a damaged prototype attack ship Air Date : 15th-Sep-2000  Read More

Season 4 Episode 13 - The Curse

When his former mentor dies, Dr. Jackson returns to his roots -- and discovers an ancient Egyptian artifact containing a Goa'uld parasite. Air Date : 22nd-Sep-2000  Read More

Season 4 Episode 14 - The Serpent's Venom

SG-1 must stop Apophis and Heru-ur from forming an alliance of their powerful forces, while Teal'c is captured and tortured by the Goa'uld. Air Date : 29th-Sep-2000  Read More

Season 4 Episode 15 - Chain Reaction

SG-1 must adjust to a new commanding officer when General Hammond steps down -- but O'Neill discovers foul play behind the general's resignation. Air Date : 5th-Jan-2001  Read More

Season 4 Episode 16 - 2010

Ten years into the future, the former members of SG-1 must send a message into the past to prevent the extinction of the human race. Air Date : 12th-Jan-2001  Read More

Season 4 Episode 17 - Absolute Power

Jackson's teammates notice a disturbing change in him when he is reunited with the Harcesis child and given the Goa'uld genetic memory. Air Date : 19th-Jan-2001  Read More

Season 4 Episode 18 - The Light

SG-1 finds a deserted Goa'uld palace, where a beautiful device causes suicidal tendencies. Air Date : 26th-Jan-2001  Read More

Season 4 Episode 19 - Prodigy

Carter must help keep a promising young cadet from throwing away a future at the SGC. O'Neill and Teal'c encounter a dangerous life form at an offworld research base. Air Date : 2nd-Feb-2001  Read More

Season 4 Episode 20 - Entity

The SGC is invaded by an alien life force that takes up residence in the base computer system -- and in Major Carter. Air Date : 9th-Feb-2001  Read More

Season 4 Episode 21 - Double Jeopardy

SG-1 must rescue an alien world from the Goa'uld -- with help from an unexpected source. Teal'c seeks revenge on the System Lord Cronus for the murder of his father. Air Date : 16th-Feb-2001  Read More

Season 4 Episode 22 - Exodus (1)

SG-1 helps to evacuate the Tok'ra to a new base -- but matters are complicated when a spy reveals their location to Apophis. The team attempts a daring plan to take out the Goa'uld's powerful fleet. Air Date : 23rd-Feb-2001  Read More