Voyager stops to assist a xenophobic species known as the Varro. This species lives on a generational ship which has housed them for 400 years. While the crew works on the Varro ship, Voyager is infested with synthetic ship-eating parasites that had been released on the Varro ship by dissident Varro. Meanwhile, Harry Kim becomes intimate with Varro scientist Tal, and develops a physiological bond with her, one that is standard in the Varro. The physiological connection alters his behavior and sways him from his duties aboard Voyager.

It is later revealed that Tal is one of the separatists. There has been a rumor of a minority of Varro that want off the ship. The parasites that Tal helped create were made to separate the individual pods of the Varro ship without destroying the ship itself. Fractures along the hull created by the parasites begin to grow as the Varro ship begins to fall apart. Voyager's docking port is seized, trapping it with the Varro ship. If the explosions get to Voyager, it would be destroyed as well. However, Harry comes up with a plan to extend Voyager's integrity field around the unstable ship. This gives the Varro enough time to stabilize the parasites.

Once the parasites have been stabilized, Voyager breaks free as the Varro ship experiences multiple breaches and the individual pods of the ship begin to break free. The majority of the Varro remain together in separate pods but the minority group that wanted to leave is allowed to do so. Later, Harry must painfully say good-bye to his recent love.

...
Wikipedia