After working for countless hours on the Replicator coding, Dr. McKay (David Hewlett) reluctantly admits that he needs help with the program. And the only available person who can match - or exceed - his knowledge is his sister Jeanie (Kate Hewlett). After working on the calculations from Earth, Jeanie sends her results back to Atlantis and heads to bed. But the calm is broken when her bedroom is stormed by four men, wielding MP-5's, who tie up her husband and drag Jeanie into the night. When news reaches Atlantis that his sister is missing, McKay travels to Earth racked by guilt for involving his sister. He is determined to find her and uncover who is behind the kidnapping. But when McKay also goes missing, it's up to Lt. Col. Sheppard (Joe Flanigan) and Ronon (Jason Momoa) to figure out who has stolen the Replicator information... and the only two people who have the knowledge to understand it.