Haunted by a disturbing dream, Rush seeks out Young to tell him that he had visions of Colonel Telford working as a spy for the Lucian Alliance, the group that attacked the Icarus planet. The two form a plan to have Telford switch consciousnesses with Rush again, so that Rush can attempt to contact the Lucian Alliance in order to confirm their suspicions.
Young speaks to Scott about the issue, since he also had residual memories from Telford, and Scott is incredulous at the accusation. Young then shares with Scott the knowledge that Telford was once a spy in the Lucian camp, and while there, he knew about a deadly plot to attack a Stargate base, and did nothing. Young backpedals, saying he thinks it may not be Telford's fault - there are known methods of brainwashing, and Telford may be a victim of them.
Once Telford is onboard the Destiny, Young goes to General O'Neill - at great risk - to tell him about the plan and have Rush tailed.
Since he shared Telford's memories, Rush has a relatively easy time finding what he needs in Telford's house: the key to a lock box, and in it, a cell phone with suspicious phone numbers. He calls one, and arranges a meeting, with unseen surveillance always close behind. The Lucians take him to a secret location, and waste no time telling him that they know he's not really Telford, but someone who switched consciousnesses using the communication stones. When he denies it, they stun him and drag him into a cargo ship - totally concealed from view - and abduct him. The Earth security forces try to save him, but are too late, and report the scene back to O'Neill. Dr. Jackson, a Stargate scientist on Earth, urges the General to sever the stone connection to save Rush's life, but Young asks for more time with Telford - he hopes to get the information he needs - and O'Neill agrees.
Back onboard Destiny, Young confronts Telford on his involvement with the Lucians, to no avail. Their heated standoff comes to blows, and Scott and Greer have to rush in to break up the fight. Young decides to amplify the pressure, and brings General O'Neill onboard via the communication stones. His presence causes Telford to confess he was a spy, and believes in the Lucian cause. Young asks permission to use unconventional methods of information gathering. O'Neill consents.
But things are getting more dangerous for Rush, as Kiva - the leader of the Lucian operation - isn't buying his cover as Telford, and begins using alien torture devices on him to get him to give up his real identity. Rush is no match for his interrogator. Once Kiva learns that he is Dr. Nicholas Rush, she immediately brings him to the center of their operation: A planet with similar geological attributes to the Icarus planet, thus able to dial the ninth chevron to Destiny. They've already done the bulk of the engineering using Rush's work (stolen by Telford) - and they force Rush to complete the final steps in their plan.
Young, having tried every humane tactic available to him, now turns to torture on Telford. He seals the man off in a room by himself, and has Brody vent the air from the room. With his chance at survival slipping away and Young looking coolly on, Telford staunchly refuses to surrender.