To ensure the mission to steal a Zero Point Module is a success, Dr. McKay (David Hewlett) proposes to use Dr. Weir (Torri Higginson) and her nanites to access the Asuran collective and guide them; should the Asurans take her over, McKay would activate a kill switch on the nanites, which would also effectively kill Weir.
With their experimental jumper ready, Sheppard (Joe Flanigan) leaves Teyla (Rachel Luttrell) in command of Atlantis.
Weir leaves McKay, confronts Oberoth and uses his power to freeze all the Asurans, even tricking him into believing that he has captured the team, all to buy Sheppard enough time to upload the programme.
The Apollo lays down covering fire long enough for the team to land in the fighter bay and carries them back to Atlantis.
Now fully powered, the city moves to M35-117, a back-up planet, by order of Sheppard and makes a rough landing onto its ocean.
Dr. Zelenka (David Nykl) announces that the Asurans have begun their attack against the Wraith, meaning Weir's sacrifice was not in vain.
[1] Carl Binder wanted to do a heist episode during the off-season, though the writers had no idea where it would fit in the overall season arc.
[3] Amanda Tapping requested that showrunners Mallozzi and Mullie not give her a big part for the episode, as she was in the Arctic filming for Stargate: Continuum.
[5] While filming Weir guiding the team to find the ZPM, the fact that she can see "everything" without looking at anything was a hard sell for an actor, but with Higginson's drive in her eyes, this would make the scene more believable for the audience.
[6] In the United Kingdom, "Lifeline" received 443,000 viewers, placing Stargate Atlantis as number six in the top ten broadcasts for Sky One for that week, behind The Simpsons and Prison Break.