While exploring an uncharted asteroid, Chakotay, Kim and Torres stumble upon what appears to be an alien burial ground. Not wanting to desecrate the site, Chakotay and his team decide to make some quick anthropological observations and then return to Voyager. But before they finish their study, a subspace vacuole — a dimensional distortion — forms and begins to fill the cavern they're investigating. Alarmed, Chakotay orders Voyager to beam them up. But when the Away Team appears on the ship, there is only Chakotay, Torres and the body of a recently deceased woman.
In the meantime, Kim finds himself trapped inside a ceremonial burial pod on an alien planet in another dimension; he has somehow switched places with the corpse. Freed from the pod, Kim is told that he's on the homeworld of the Vhnori people. The Vhnori think that Kim has come from the "Next Emanation," or afterlife, and they are disturbed when he reveals that he has just come from a place that contained the dead bodies of many Vhnori.
On Voyager, the Doctor is able to revive the corpse — a woman named Ptera. When Ptera realizes that she is not in the Next Emanation with her deceased family members, she becomes hysterical. Later, she reveals that her people believe that when they die, the vacuoles take their bodies to another plane of reality. To learn that the distortions merely take their bodies to a barren asteroid is difficult to accept. Not long after, another vacuole forms, and deposits a second corpse onto the ship, and still later, a third.
After hearing Kim's story about the bodies on the asteroid, a Vhnori man named Hatil — who was about to submit to euthanasia to ease his family's burden in caring for him — changes his mind about dying. On Voyager, Ptera wants to be sent home, even if that means dying a second time. The crew attempts to beam her into a forming vacuole, but the procedure doesn't work and when they retrieve her, Ptera is dead.
Time is running out. The vacuoles are damaging the ship's warp core. If the crew doesn't find Kim soon, they'll have to leave him behind. On the Vhnori world, Kim figures out a way to escape. He'll take Hatil's place in a burial pod, allowing Hatil to fulfill his own escape option and Kim to transfer to his universe when the next vacuole delivers the occupant of the pod into the other dimension. The plan works, and Kim's body appears on Voyager, where the Doctor is able to revive him.