The ship enters a nebula and finds it is a living creature.
Voyager enters a dense nebula in search of material to refuel and soon discovers that the cloud is itself a living thing which the ship has injured. Janeway deals with the damage while a restless Chakotay tries to reach her through a guided spiritual journey meant to calm her.
The story gives viewers a first look at Chakotay's native heritage and his spirit guide, which became a recurring element of his character. It also explores how the crew copes with the mounting stress of being cut off from home, and it ends with the ship learning to be more careful about the consequences of its choices.