Plot

Destiny is in poor shape following its recent battles and has virtually no back up systems remaining. As the ship approaches a star for refueling, Eli wants to test his theory that he can dial Earth. While the simulations suggest that it will work fine, Rush is dead set against, arguing there are too many anomalies in a star for it to work. Most are suspicious of his motivation however. With most of the crew in the gate room waiting to leave through the gate they receive a message - from a second Dr. Rush coming toward them in the shuttle. He claims to have traveled back in time 12 hours and relates what happened. The anomaly and time shift also present a solution to their need for redundant systems.—garykmcd

After a group meeting where Volcker and Brody state that Destiny is in an advanced state of disrepair and that there's probably no hope of fixing her, Eli announces that he and Gin had figured out a way to dial the gate back to Earth from within a star.

Young, Telford, and Wray decide that the only option is to take everyone back home and prepare to go through with the dialing. Rush is opposed to this decision, both because he thinks it is too dangerous, and because he thinks that the Destiny's mission, to discover the meaning of the universe's source code, is too important to abandon. He gets permission from Young to present his case to the crew before they evacuate and to see if anyone wants to stay. Young reveals that he will stay with Rush on Destiny and Rush says they need at least ten more people to work the ship. Before they can present Rush's case, however, they are called to the bridge by Telford.

When the Destiny dropped out of FTL, they discovered something orbiting the local star, the one they are set to pass through. Their signals seem to show that it's Destiny's shuttle. They get a radio signal from the shuttle's pilot, Dr Nicholas Rush who states that he must have traveled back in time and that he comes from a timeline where Destiny has already gone through the star and attempted to dial Earth, with disastrous results.

This duplicate Rush is brought on board where he relates his story. He made his presentation to the assembled group and a number of then (Greer, James, Scott, Chloe, Eli, Volcker, Varo, TJ and a couple of extras) volunteered to continue on with the mission. They dial the gate back to Earth and Telford goes through to make sure it's safe. The others are supposed to follow in an orderly fashion but there begin to be problems with the gate. Rush and Eli manage to stabilize it and the people hurry through in a panic. As they're going through the ship begins to suffer physical damage. Young and the others who had intended to stay behind also decide to evacuate, with Rush volunteering to stay behind to operate the gate. After everyone is gone Rush uses the communication stones to contact Earth where he discovers that only Telford made it through to Earth.

Hearing this, the present day Young decides to abort the dialing of the gate. Camille Wray uses the stones and confirms that Telford arrived on Earth. As they pass around the star they see the other Destiny orbiting. It is damaged and falling towards the star but the living quarters seem to be intact and Rush and Brody come up with the idea of raiding it for supplies.

The crew gates over to the dying Destiny to get the supplies and repair parts which they need. As the Destiny begins to fall into the star they evacuate but the alternate Rush sees some devices which will double their weapons capacity. Ordering everyone else to evacuate, Telford returns to help the alternate Rush. There he accuses Rush of doing something to sabotage the gate. Rush accuses Telford of getting everyone killed by ignoring the dangers of dialing within a star. They fight and Rush accidentally pushes Telford against an open piece of machinery, electrocuting him. He then runs off.

Scott and the main Rush return to check on alternate Rush and Telford and find the Colonel dead. Rush runs off after his doppleganger and finds him in the chair room screwing up his nerve to sit in the Ancient chair. With Rush's help, the alternate Rush sits in the chair. Rush then hurries back to the gate room where he and Scott escape to Destiny just in time to witness the alternate Destiny falling into the star.