During an off-world mission Colonel Sheppard unknowingly becomes host to an alien entity, which infects others in Atlantis and afflicts them with terrifying nightmares.

“Doppelganger” Facts:

• “Doppelganger” was nicknamed “Nightmare On Atlantis Street” around the show’s production office.
• It’s the final episode for Kate Heightmeyer (Claire Rankin), the Atlantis base’s resident psychologist. She was first introduced when Teyla was having Wraith issues back in Season One’s “The Gift.”
• This episode is the first time in a decade that Stargate revisited the idea of alien lifeforms that exist in crystalline form. It goes back to the early SG-1 episode “Cold Lazarus” — only in this case the alien is pretty much evil incarnate.
• Rodney’s line about his father reading him “Moby Dick” as a child comes from writer Robert C. Cooper’s own childhood experience, when his father took him to see the movie Jaws. “I think I probably didn’t sleep for two years,” Cooper said. “Honestly, I probably needed therapy!”

“Doppelganger” on GateWorld:

• Episode Guide
• Episode Transcript
• Fan Reviews
• Photo Gallery
• Screencap Gallery
• Discussion Forum
• Interview with Robert C. Cooper (2007)
• Interview with David Hewlett (2007)
• Interview with Martin Gero (2007)
• Interview with Joseph Mallozzi & Paul Mullie (2007)

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Rewatch “Doppelganger” this week! Then post your comments below, or head over to the “Doppelganger” discussion forum and see what people were saying back in the day. What are your favorite moments?

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