Weir博士重获新生,McKay博士试图拯救遭受复制者攻击后早已成千疮百孔的亚特兰蒂斯。可供使用的能源仅可维持24小时,又无法使用星际之门,亚特兰蒂斯小队能否再次战胜世界末日...... McKay与Sheppard计划从复制者的手中夺回ZPM。而与此同时,Samantha Carter会同Apollo正在找寻传说中遗失的城市--亚特兰蒂斯。McKay他们的计划能否成功?Carter能否找到遗失城市的所在?After the explosion of Michael's medical compound, which caved in, trapping the Atlantis team and the marines, Colonel Samantha Carter sends a rescue party along with a medical team and the combat engineers, as well as a new addition to the Atlantis team, Captain Alicia Vega. As the rescue starts, it appears that the team has been split into the two surviving groups of Ronan and Lt. Colonel Sheppard, and McKay and Major Lorne. When McKay finds Michael's hard drive, it contains a lot of data about his operations. Suddenly, McKay realizes that, when the compound self destructed, it sent out a subspace message that alerted Michael of their presence. With the Daedalus now in orbit, Michael appears and they engage into combat. As the battle progresses, they realize that Teyla could be aboard and they decide to mount a rescue mission to retrieve her. When they're aboard, it appears that Teyla is nearing birth and they'll have no chance of retrieving her in time.