Episode

Original Air Date (United States): October 19, 2007
Original Air Date (Canada): October 22, 2007
Original Air Date (United Kingdom): October 30, 2007
Written by: Robert C. Cooper
Directed by: Robert C. Cooper
Guest stars: Claire Rankin (Dr. Kate Heightmeyer), Jewel Staite (Dr. Jennifer Keller), Kavan Smith (Major Evan Lorne), David Nykl (Dr. Radek Zelenka), Linda Ko (Marie), Yee Jee Tso (Technician)

Short Summary: After encountering an intriguing crystal, Sheppard and team head back to Atlantis. Then the Atlantis crew finds themselves having nightmares that are strangely connected. The effects of the nightmares begin breaking through to their waking hours, and it becomes an all-out race to save lives.