The episode begins with the Enterprise traversing a series of spatial anomalies in the Delphic Expanse. When confronted with a particularly dangerous anomaly, the Enterprise is rescued by Andorians using a tractor beam. The Andorians claim they are interested in helping Enterprise in its mission to subvert the deployment of a Xindiweapon against Earth, in the interest of forming a close alliance with humanity. In the end, however, it is revealed that the Andorians actually have no interest in helping the humans, but rather are self-interested: they merely want to acquire the weapon to give them an upper hand in a border conflict with the Vulcans.
Before the Andorians reveal their true motives, they work together with the humans to locate the site of testing of the Xindi weapon. In an armed battle with the Xindi, the Andorian/human alliance captures the weapon and stores it aboard the Andorian vessel. Captain Archer then learns of the Andorians' real plan and, back aboard the Enterprise, he threatens to detonate the weapon unless the Andorians release it from their ship. This ultimatum is resisted by Shran, the commander of the Andorian ship. In several private moments of Shran's throughout the episode, Shran is revealed to consider Archer a man he trusts and considers an ally, and that he would prefer not to do the mission as it means betraying him. When Archer orders the initiation of the detonation sequence, however, Shran obliges and releases it. The weapon explodes, damaging the Andorian ship but leaving the Enterprise virtually unharmed. The Enterprise's encounter with the Andorians finally is over—for now. As Enterprise leaves the Andorians, they receive a message, containing highly detailed information about the prototype. The message came from the Andorian ship, disguised as white noise as "whoever sent it obviously didn't want it to be noticed." Realizing Shran did indeed help them, Archer laughs and begins having the data studied.