Captain Archer and the crew discover a fully inhabited, civilized though less advanced Earth-like planet. Disguised to look like its inhabitants, they pay the planet an exploratory visit where they learn that a pernicious illness is afflicting the local population. As Archer seeks to help them find the malady's source, he finds himself in a close encounter with a comely female alien.

Suffering from damage inflicted in the Romulan minefield and unable to complete repairs on their own, Archer orders a distress call to be put out. A response leads Enterprise to a repair station, which surprisingly has no crew aboard it and is run by computer. Repairs on Enterprise are carried out quite efficiently and quickly, though the price for all this is much higher than the crew could've guessed.

When a lethal neutronic storm approaches faster than Enterprise can escape, the crew take shelter in the maintenance shafts inside the warp nacelles. They also provide refuge to a group of aliens, who aren't exactly honest about themselves.

The Enterprise crew find a small craft drifting in space and are surprised to find it contains a human corpse. More questions arise when the Suliban and Tholians make claims to the craft.

The remnants of an alien ship and two frozen cybernetic bodies are uncovered in the arctic by a research team. These aliens soon thaw out and flee Earth, taking the research team with them. Starfleet orders Enterprise to find them, but the crew aren't prepared for just how dangerous these aliens really are.

A powerful telepath makes contact with Hoshi and offers to help Enterprise find the Xindi ... for a price.

While dissension among Xindi ranks festers, Enterprise tries to recover from a devastating attack.