The members of SG-1 arrive on P3X-989 and are knocked unconscious. They wake up and return to Earth only to find that they are not quite themselves.

The banished Goa’uld Hathor is found in an ancient sarcophagus Earth, and takes over the S.G.C. with hopes of raising a new army against the System Lords.

A mysterious affliction wipes out the entire population of a planet, plus an SG team — except for one young girl. Carter befriends her, but learns that she is being…

Teal’c returns to Chulak to stop his people from implanting his son with a larval Goa’uld.

Daniel is taken captive by an alien with a hidden agenda, while SG-1 is made to believe he is dead.

During an off-world assignment, Jack is struck down by energy from a blue crystal… which creates a duplicate of him that returns to Earth in Jack’s place.

SG-1 discovers a race of attractive people who age extremely rapidly. The situation becomes personal when O’Neill begins to suffer from the same accelerated aging, and must live out the…

Members of SG-1 become infected with an alien virus that turns them into primitive beings. Dr. Fraiser must find a cure to save the team and the alien population from…

Mulder and Scully uncover strange occurrences in an elderly care home when one of the nurses is attacked by an unseen force she claims to be one of the 90…

Sam and Dean investigate a string of suicides committed by people with little in common other than the identical, grisly method of death – slow, self-administered disembowlment. All of the…

Sam and Dean investigate a brutal death and discover that the killer is a lycanthrope: a werewolf.