T'Pol receives a mission from the Vulcan High Command. She informs Archer that Admiral Forrest will be calling later about it. Though the letter of the mission is met by assigning Mayweather as her shuttle pod pilot, T'Pol meets privately with Archer and asks that he join the mission - she trusts him. It seems that T'Pol was once trained in reconnaissance retrieval, and now she is to capture a rogue, surgically-altered, Vulcan agent that eluded her before.
Archer, T'Pol and Mayweather easily track the fugitive, Menos, to a cantina and after a brief phase-pistol fight, they capture him. Menos then starts to play on T'Pol's sense of fairness and honor. He has a good, though hardly opulent, life, with a family... and he's dying. T'Pol gets confused and tries to disprove his story, but is unable to.
On Enterprise, Trip finds the daily burdens of command more than he expected. It gets worse when a Vulcan ship arrives with a personal message from Admiral Forrest to Archer. Trip impersonates the Captain so as not to let the Vulcans know the Captain is away. It turns out the message was only a water polo score.
T'Pol relates to Archer that she's been having flashbacks to her previous hunt of Menos. They started when she first got the orders a few days ago. During that previous hunt, she killed another fugitive. Because of the ramifications of killing on Vulcans, she sought treatment on P'Jem... where they ultimately repressed her memory of the incident to the point where she had no knowledge that it had ever happened.
Menos arranges his escape, but is thwarted by the away team when Archer helps T'Pol to focus on her mission. It turns out that he was trading in bio-toxins as the Vulcan High Command had reported. Back on Enterprise, T'Pol and Archer talk about the ramifications T'Pol's emotional conflict. As she leaves, T'Pol tells Archer that if he ever needs someone to trust...