Sub-commander T'Pol receives a covert mission from the Vulcan High Command. She informs Captain Archer that Admiral Forrest will be contacting him later about it. T'Pol remains tight lipped despite Archer's enquiries as to the exact nature of the expected 3 to 5 day diversion. Though the letter of the mission is met by assigning Ensign Mayweather as her shuttle pod pilot, T'Pol meets privately with Archer and asks that he comes as well on the mission since she needs someone she trusts. In conversation with Archer, she reveals that she was trained 17 years earlier in reconnaissance retrieval, and now she is to capture one of six rogue, surgically altered, Vulcan secret agents that eluded her before.
Archer, T'Pol, and Mayweather, easily track the fugitive, Menos, to a cantina on the icy Pernaia Prime moon. After a brief phase-pistol fight, they capture him, but are unable to leave due to a build up of acidic ice. Menos then starts to play on T'Pol's sense of fairness and honor. He has a good, though hardly opulent, life sustaining his family with an honest job (hauling spent warp injector casings), but apparently he is dying. T'Pol becomes confused and tries to disprove his story by searching for biotoxins in his ship, but is unable to locate any.
On Enterprise, Commander Tucker finds the continual interruptions of command more than he expected. It gets worse when a Vulcan ship arrives with a personal message from Admiral Forrest to Archer. Tucker impersonates the Captain so as not to let the Vulcans know the Captain is away. It turns out the message was only the score of a sporting event.
T'Pol relates to Archer that she's been having flashbacks to her previous hunt of Menos. They started when she first received the orders a few days earlier. During that previous hunt, she shot another fugitive called Jossen. Because of the ramifications of killing on Vulcans, she received "fullara" treatment on P'Jem where her memory and emotions of the incident were repressed to the point where she had no knowledge that it had ever happened. Meanwhile, Menos arranges his escape by starting a fire, but is captured by the away team when his cloaked hiding space is detected. It is discovered that he was hauling biotoxins as the Vulcan High Command had reported. On Enterprise, T'Pol and Archer talk about the ramifications of T'Pol's emotional conflict.