Deadman Switch (S03E07)

SG-1 travels to planet PJ6-877 for a routine recon. Almost immediately after arriving, they are snared in an invisible forcefield by alien bounty hunter Aris Boch. Aris takes them to his cargo ship, which is completely invisible from the outside. He has come to this planet to hunt a Goa'uld named Kel'tar, who is wanted by the evil system lord Sokar. He attempts to solicit help from SG-1, in exchange for their freedom — then informs them that should they refuse to participate, he will take them to Sokar. Apparently, there are sizable bounties on the heads of Teal'c and Maj. Samantha Carter, and a reasonable bounty on the head of Col. Jack O'Neill, but Dr. Daniel Jackson could probably only be traded for a day's rations. After an unsuccessful escape attempt, SG-1 agrees to help Aris Boch catch his Goa'uld prey. Carter remains with Aris, at a safe distance from the cave in which Kel'tar is hiding, while O'Neill, Daniel and Teal'c go in for the retrieval. When Kel'tar is captured, he informs SG-1 that he is not Goa'uld, he is a Tok'ra named Korra. If handed over by Aris, Sokar would torture Korra to gain information that would endanger many other Tok'ra. SG-1 and their new Tok'ra ally must find a means of escape or try, against all odds, to convince the cold-hearted bounty hunter to do the right thing. Unfortunately, Aris Boch's survival is dependent on something only the Goa'uld can give him. In order to get it, he must trade Korra's life for his own. (Metro-Goldwyn-Mayer (MGM))