leaves its current galaxy, Young addresses the assembled crew and informs them that they will have to begin rationing since they may be in the void between galaxies for some time. He also informs them that because they are moving beyond range of the Stargates, Eli, Scott, and Chloe are stranded behind them.
Rush calls Young to the command center and tells him that the ship is trying to conserve power, and that the systems are activating because the computers have determined that it will be unable to cross the void on its existing power. The scientists gather to review their options, and Brody notes that they are only short 5% of the energy that they need to reach the next galaxy. He suggests that they upgrade the hyperdrive engines to gain the necessary performance, but Rush insists that they'll need an expert from Earth. Discussing the matter, they conclude that the best-qualified person is Dr. Amanda Perry. Young agrees but Rush explains that there's a problem: Perry is a quadriplegic on a respirator.
Young assembles the female crew and asks for a volunteer to make the exchange with Perry. James agrees so that she can see her family while she's on Earth. However, she ends up in Perry's body and immediately panics. She returns to her original body, knocking the communication stone on the floor. Perry, who was just coming to enjoy her "new" body, returns to Earth. Camille volunteers and arrives on Earth in Perry's body. Major Peterson informs her that Strom wants to see her, but Camille says that she plans to spend her time with her girlfriend Sharon.
, Johansen examines James and assures her that she's fine. James is ashamed that she failed Young, but Johansen assures her that he won't hold it against her. When Rush and Perry arrive, James quickly leaves, going out into the hallway to her quarters. However, she suddenly goes blank and freezes in place.
Camille and Perry's aide, Mary, go to Sharon's home and Camille tells her girlfriend about her temporary situation. The couple shares an awkward kiss.
Perry and Rush begin their work but are interrupted when one of the hyperdrive modules explodes. The ship drops out of hyperdrive, and Camille and Perry temporary revert to their original bodies. In the aftermath of the explosion, Johansen, James, and her teams get the injured to the sickbay. Rush informs Young that they're adrift in the void and Volker sends a kino to investigate the damaged sections.
James tells Johansen about the period when she blacked out, and explains that she woke up in a different section of the ship. Johansen dismisses the incident as the aftereffects of a concussion and has James stay for observation. Meanwhile, one of the rescue teams finds Franklin. He's in shock but appears to recognize and react to James.
As they begin repairs, the Stargate activates as a wormhole forms. Greer prepares to open fire on the intruders... and Scott, Chloe, and Eli step through the gate.
After Mary has given Sharon instructions on how to care for Camille in her current body, As Mary feeds Camille, Sharon talks about what she has been doing since Camille left. When Camille chokes while trying to talk, Sharon takes over the feeding. Camille wonders if her girlfriend isn't disturbed, but Sharon insists that what's important is that Camille is home again.
Johansen checks the returning trio, who explain that they kept activating the Stargate until it made a connection to Destiny
, Young congratulates them on their return and then puts Eli to work restoring the FTL drives.
James helps feed the shell-shocked Franklin. She tells Johansen that she's been having nightmares of being trapped in a dark room where someone else has taken over her body.
Amanda in Camille's body comes to see Eli in his quarters, where he's working on the equations. They know each other from Earth and she teases him, and admits that Rush used to tease her. She admits that she has feelings for Rush, much to Eli's surprise. When he acts startled, Amanda accuses him of thinking that the handicapped can't have romantic feelings. Eli explains that he simply didn't think that anyone could possibly care for Rush.
Rush and the others report to Young that the blowout may be good news. The strain of FTL drive blew out the least efficient of the sixteen modules, meaning that the overall efficiency has increased and they'll be able to cross the void. Now they need to bypass the damaged systems, and Eli says they can use the repair drone they found in the cargo hold to make the repairs. After the others leave, Young asks if Rush believes they can succeed. The scientist admits that the odds aren't good, and suggests they use the chair to gain the necessary knowledge. Young agrees, but only if he uses the chair, refusing to put anyone else at risk.
Scott goes out in the shuttle to guide the robot drone and make repairs. Meanwhile, Young prepares to send a team back to the planet to gather supplies so they can cross the void. Johansen insists on going, and when Young refuses she points out that he's trying to protect her because she's pregnant with his child. Young reluctantly agrees to send her along and Eli sends a kino through. He doesn't see the point since they just came from the planet and it was safe. Young insists, and they discover two alien fighters on the other side. They destroy they kino, but are unable to activate the Stargate without a remote. However, the crew is cut off with no way back.
The crew makes their repairs over the next three weeks, and continues on with their lives as best they can. Scott leads jogging sessions, Brody makes a still, and James feeds Franklin. On Earth, Sharon continues to take care of Camille. Camille finally sends her out for groceries, saying she'll be fine on her own. Once Sharon is gone, Camille tells Mary that she thought Sharon needed some time on her own.
Rush and Amanda finish removing the damaged module and bypassing the control systems. Rush takes her to the mess room and offers some of Brody's alcohol. As they drink together, James talks to Chloe about her continuing dreams of being trapped in a dark room. Amanda tells Rush that she's reluctant to finish repairs since she will then have to go back to earth, and her own body. Meanwhile, Chloe takes James to Young and inform him that James is the one that sabotaged the FTL module.
Rush walks Amanda back to her quarters and she asks if he realized that she had feelings for him when they worked together on Earth. Rush figures that she was just feeling sorry for him after he lost his wife. Amanda invites him into her quarters and then starts to kiss her. Rush backs away and explains that given his recent experience with his wife in the chair's dream scenario, he can't bring himself to be with Amanda. Amanda is glad to at least give him a hug since she has a functioning body. However, Johansen arrives to tell them that they have a problem and takes them to the interface room.
On Earth, Camille begins to panic when Sharon doesn't return. Sharon finally arrives and explains that she was delayed at the grocery store. Camille explains that she couldn't help obsessing about everything bad that could have happened to her. Sharon points out that she has the same feelings every day when waiting for Camille to come home. Camille suddenly has a seizure and passes out.
Young tells Rush and Amanda that they now believe that when James knocked the communication stone off the table, her mental imprint wasn't cleared from the programming. The aliens detected it and used the circumstances to switch places with James and then sabotage the FTL. Rush figures the aliens still can't track them, but Young figures that the alien could have sent a signal, or calculated their location and informed the others when the switch ended. They realize that the aliens will soon arrive and begin another assault to gain control of Destiny
Major Peterson comes to collect Camille, informing her that Amanda will be returning to her body now that she's completed repairs. Camille and Sharon exchange goodbyes.
Before going to the interface room, Young writes out letters to Scott and Johansen. He tells the crew that they have no choice but to fight back and hold off the aliens as long as they can before Young can access the computers via the chair and make their escape. He puts Scott in command and orders Greer to repel boarders, and then goes with Rush to the chair.
Franklin comes out of his shock just enough to mutter the word "chair" to James.
As the alien attack shakes the ship, Rush prepares to activate the chair. James arrives and tells them that Franklin has regained consciousness, and that he wants to use the chair. Rush agrees, noting that Franklin has already used it once and has the proper brainwave configuration from his first attempt. Young disagrees but Rush says that they should give Franklin the opportunity to choose. With time running out, they go to see Franklin in sickbay. He agrees and they take him to the chair. When it activates, the room fills with freezing mist and Young and Rush are forced to leave.
Greer prepares to repel the aliens as they get past the ship's defenses, but the FTL drives activates and Destiny
departs. Once they're safe, Amanda realizes that she has to return to her own body at last. She goes to the communication room and tells them that she hopes they need her again. Rush half-seriously says he can arrange that. Amanda gives him one last kiss and then returns to her own body.
Young and James go back to check on Franklin. When they open the chamber door, they discover that Franklin has disappeared.