Weir and the team visit an advanced civilization that split off from the Lanteans thousands of years ago, but discover that they may not have left Atlantis in peace.

Teal'c discovers a world where people are being savagely attacked by an elusive creature, leading SG-1 to a stunning discovery about its potential origin.

Following a meeting with Janet, Tommy has yet another confrontation with Johnny; Teddy's conjugal visits with Ellie prove to be a letdown; and Franco tries to befriend his new girlfriend's…

Spencer is apparently abducted by aliens and then returned to earth the next day inside a crop circle. Also, the town is visited by the congressman whose committee is responsible…

Kyle links his memory to a missing professor, but finds a welcome distraction when he joins the basketball team. Meanwhile, Nicole gains a better understanding of Kyle's unique situation.

Tom and Diana's investigation into a series of gruesome murders leads them to uncover another conspiracy within the government. At the 4400 Center, Shawn receives a gift from another returnee…

Ronon Dex is captured by the Wraith and returned to his homeworld, where he is haunted by his past as he is forced to once again become their prey.

When Baal comes to Earth seeking help, Stargate Command must capture his clones and determine which one is the genuine article.

The crew faces more than accustomed when rescuing a man from his burning apartment; Sean has a request for Maggie's dad; Franco thinks his new girlfriend is hiding something from…

Jack Carter accidentally shoots Henry while suffering from short-term memory loss, meanwhile a visit from a noted scientist may hold clues into to his sudden memory loss.