Rush seals himself in a corridor and takes out a transmission device fastened to an Ancient communication stone.
On Earth, Dr. Bill Lee has a similar device on his desk. Rush is working with his version and realizes he's in contact with Lee.
Scott and his team explore the ship and try to contact Rush when they come to a bulkhead door. Eli picks up the radio and says that Rush went to find a bathroom. Scott tries to open the door, wondering if something important is on the other side. Eli detects their efforts on an internal scanner but notes the warning light is flashing right. He tries to open the door from the control center and succeeds, but they discover a breech on the other side. Eli manages to close it and warns that there are other sections of the ships that have depressurized. Rush returns and tells everyone to meet him in the Gate room immediately.
Once everyone has gathered, Rush reveals he has five Ancient communication stones that let the user take control of someone at the other end in contact with a stone. Rush claims he already has contacted Earth and there's no way they can rescue them. Armstrong asks to use one of the stones but Rush says that he spoke with General O'Neill, who has placed him in charge. Armstrong and Scott don't believe him, but Armstrong collapses before he can protest further. Johansen determines he's bleeding internally. Camille Wray, the IOA representative, disagrees and the others join her. Scott informs them that Young put him in command all SG personnel will obey him. However, he agrees with Rush that they have to work together and spread out from the Gate room. Scott then talks privately to Rush and says he'll back him now, but he needs to find a way to get them back to Earth.
The group reviews their provisions and Camille notes that Greer was in detention. She wonders what they should do about it now and Greer says that it's up to Scott and Young if he recovers. When Camille says that they'll see, Greer wants to pursue the matter but is called way to check for leaks. As he goes, one of the soldiers secretly takes some food.
As Scott checks out the hallways, he sees a metal drone fly by and follows it.
Young wakes up and asks Johansen what's going on. She brings him up to speed and warns him that the life support isn't working. Young doesn't believe Rush's claim that O'Neill put Rush in charge, but realizes that he can't get up when he discovers he can't feel his legs.
Scott follows the drone to Eli, who is controlling it and has discovered it has a camera. Eli calls it a kino and figures they can use it to investigate the damaged parts of the ship. As they leave, Scott admits that he hasn't been active much longer than Eli.
Johansen tries to assure Young that the paralysis is temporary but admits they don't have a doctor or the proper diagnostic equipment. He notes her tour was over two weeks ago and apologizes, but Johansen says it's not his fault. Young tells her to bring Rush.
Eli and Scott arrive at the command center and Rush is impressed with the kino. He explains that the carbon dioxide scrubbers are failing. Scott and Greer head for the scrubber node, which is filled with black goo.
Chloe tends to Armstrong, who is recovering in a private chamber. He tries to take the heart-thinner pills for his heart, but Chloe warns that it will aggravate his internal injuries. The senator tells Chloe to find out what's going on and assures her he'll be there when she comes back. However, she takes the pills as she goes.
The team deserves that the Ancients' carbon dioxide filters are breaking down. Rush figures that if they can seal the leaks, they might have a couple of days before they suffocate. When Scott insists that he devote his efforts to dialing back to Earth, Rush says that it won't work but agrees to try.
Rush and Eli find two shuttles and Greer takes a team to one of the docking sleeves. The door won't close and they find that the shuttle is leaking and the shield isn't preventing complete leakage. Rush and Eli go to help them and discover how to seal the door but only from inside the shuttle.
Young begins to regain use of his legs. Johansen explains to Young and Chloe to her father that they can't jam the shuttle door long enough to let someone get out due to a safety mechanism, and the ship was damaged after some battle. They only have an hour left before they lose their breathable atmosphere. Rush realizes that someone will have to go in and close the door to give them at least 24 hours of air.
Eli documents what's going on, insisting that someone might find it after they're dead and can use it to help themselves in the future. Rush goes over the list of personnel and starts determining who they can do without themselves. The others object but Rush notes they have no other choice. Scott and Johansen explain the situation to Young, who says that he'll sacrifice himself and Scott can handle command. Johansen doesn't want anyone to sacrifice themselves. Young insists that he'll do it and tries to get up, but Scott refuses to obey his order. Chloe arrives and reveals that her father has disappeared. Armstrong has taken a gun and gone to the shuttle, and is holding off Greer and the scientist, Franklin. With time running out, Franklin can't complete the repairs and Armstrong asks Greer what to do.
Chloe and Scott arrive just as Senator Armstrong seals himself into the shuttle. His daughter pounds on the door while Scott glares at Greer, who admits Armstrong was dead on his feet. Armstrong passes away as Scott embraces a sobbing Chloe. She pulls away and runs off to attack Rush. Scott manages to pull her away as she blames Rush for killing all of them. He tries to apologize and insists there was no other way. Rush tells her how important the discovery of the ship is and how Senator Armstrong believed in the project. He insists that all of the human lives that have been lost are valuable, and he promises that no one else will lose their lives in vain. Chloe walks away without a word.
Young makes his way to the Gate room and tells the others that they've lost Armstrong. He asks Camille to keep morale up.
Scott goes to see Chloe, who is sitting in the observation port. She admit she still can't accept that her father is alive. Scott asks her to talk about him, saying he'd like to know about the man who sacrificed his life for him. She talks and Scott tells her that her father would have wanted her to go on.
Eli wonders if Rush cares about Armstrong's death and Rush insists that he does. However, he says that he also has to devote his efforts to saving the others. He has learned that the ship's name in Ancient was Destiny, and that the Ancients were never aboard the ship. The Ancients sent it out on its own and planned to use the Stargate to board it when it got where they were going. When they Ascended, they gave up their project. Eli apologizes to Rush before going back to work.
Major Kevin Marks easily find the address for Earth in the database and Young orders them to set it for Earth. Rush realizes what they're doing and runs to the Gate room. he warns that it's a waste of time and power. Young insists they need to show the others that they're trying. The ship suddenly comes out of FTL drive and Rush realizes that they've neared a planet with a Stargate. The Ancients sent other drone ships ahead with Stargates, and the Destiny computers sensed when it was near one. Rush told the computers to seek out Stargates that might have the resources they need. Eli sends a kino through and they confirm the nearby planet can support life. The computers bring up four other planets within range but Rush notes that they are locked out. Young prepares to put a team together but Rush finds a timer and warns that after 12 hours, the ship will automatically jump back to FTL.
Rush and Young put together a team and Eli volunteers. Young notes that he's already helped them and agrees. He wonders if Rush should go, but Rush notes that he's best suited to assess if the planet is suitable for long-term survival. Young puts Scott in charge and tells them to prepare for departure. In private, Scott expresses his reservations about Eli but Young insists that they're going to need everyone to step up. As Scott goes, Young tells him to keep an eye on Rush. As Young watches, Scott leads his team through the Gate.