Captain Archer, Sub-commander T'Pol, and Commander Trip Tucker fly down from orbit to a small colony of 76 miners in order to trade for deuterium. They initially try to barter with Tessic, the colony's leader, but he appears reluctant to part with any of the 80,000 liters in inventory, which is being held for 'someone else'. After negotiations however, a deal is struck − 200 liters of deuterium for four power cells and whatever medical supplies Enterprise can spare, on the proviso that the Enterprise crew can fix two offline pumps in two days.
Despite deuterium being a valuable commodity, Archer is startled by the lack of basic medical supplies and the run-down nature of the colony. The reason becomes apparent when seven Klingons show up to collect deuterium according to their 'regular arrangement'. The colony leaders beg Archer to stay out of sight of the Klingons, which they do, and Enterprise changes orbit to the opposite side of the planet. When Tessic informs Korok, the leader of the Klingons, that they do not have all the deuterium because two pumps were not working, Korok hits him and gives them four days to meet the order, and then beams out.
Later, when Trip and Archer attempt to talk them into fighting against the Klingons, Tessic tell them to take their 200 liters and leave. However, taking the deuterium and leaving does not sit well with Archer. After returning to Enterprise, Archer takes a trip back to the planet and convinces the leader to stand against the Klingons with their support. On board, and in preparation of the coming fight, T'Pol teaches some of the colonists how to evade edged-weapon attacks (from Vulcan martial-art Susmana), while Ensign Hoshi and Lt. Reed teach other colonists how to fire their weapons more accurately. Archer and Trip then suggest the colonists shift the entire colony to the south 50 meters, and assist in the relocation.
When the Klingon marauders arrive, the colony appears deserted and silent, especially since the pumps are no longer running. Finally the defenders show themselves, and in the ensuing fight the Klingons are lured into an area surrounded by the capped-off deuterium well heads. On cue, the wells are ignited which surrounds the Klingons with flames. Tessic then tells the Klingons to leave and never come back because they will be prepared to defend themselves. After they depart, Archer is rewarded with 2,000 liters of deuterium instead of the bartered 200 liters by the grateful miners.