B'Elanna Torres, Chief Engineer of USS Voyager leaves the ship to track down a long range probe. On the way, her shuttlecraft encounters an ion storm. Torres performs a high speed landing into the shuttle bay, assisted by a tractor pulse to slow her crash landing. Sustaining only minor injuries, B'Elanna is shown recovering in sickbay after Tom Paris, the ship's helmsman, trained medic and B'Elanna's boyfriend, examines her while she was still in the shuttle.
The crew discovers a strange piece of Klingon metal which was found when the shuttle crashed, presumably carried into Voyager after B'Elanna encountered it in the ion storm. When Chakotay brings the metal to her and they discover it came from the Klingon Empire, they exchange remarks about how the Empire may have been to the Delta Quadrant hundreds of years earlier. Harry Kim comes to B'Elanna's room later to discuss the metal as well, and after he leaves, the metal suddenly starts to pour blood all over the table. When Torres examines it further, the blood disappears. The scene changes to B'Elanna and Ensign Kim scanning the device in the engineering section of the ship, where Kim remarks that their scans seem to agree that it is simply a piece of metal and that it is very late at night for them both to be up. Neelix, the crew's head chef and official morale officer, greets B'Elanna, and reveals that he plans to throw a Klingon themed party celebrating the find of the metal out in the Delta Quadrant.
Before the party begins, B'Elanna is with Lt. Commander Tuvok, the ship's tactical officer and one of only a few Vulcans aboard. He is helping B'Elanna discuss her possible hallucination concerning the blood pouring from the metal. Suddenly, Tuvok's attitude starts an odd change, as he begins to sound very pro-Klingon in his remarks. Tuvok begins demonstrating to B'Elanna the technique for wielding a Bat'leth after B'Elanna states that it is a "crude weapon". He cuts her on the cheek with it. B'Elanna is then dismissed in apparent shock, and the scene changes to Neelix's party.
At the party, various members of the crew, including the Doctor and Seven of Nine, are shown to apparently be getting into the spirit of the party. As Kathryn Janeway, Voyager's captain, prepares to make a speech, B'Elanna witnesses reality distort; as things move in slow motion, the background lighting changes to red, and she views Klingons moving through the crowd. Suddenly, they attack and massacre the entire crowd, and when one attacks B'Elanna, she suddenly finds herself on the Barge of the Dead.
On the Barge, several Klingons are seen attempting to brand B'Elanna with a mark intended to indicate Klingons who were, due to their dishonor, destined for Gre'Thor. B'Elanna learns from Kortar, the Barge's pilot and the first Klingon who ever lived (now doomed to steer dishonored souls to Gre'Thor on the barge for killing the Klingon gods. Although it is unknown who sentenced him to this punishment.), that it is not her time. B'Elanna witnesses her mother, Miral, suddenly appear on the barge. B'Elanna awakens from an apparent coma.
It is soon revealed that she never actually came out of the crash from the shuttlecraft conscious, but was in a coma for quite some time until she could finally be revived. Thinking about all that happened, B'Elanna seems to become determined to find and rescue her mother, and goes over some ancient scrolls from the Klingon mythology which are in Voyager's database. Learning of a ritual that the warrior Kahless once undertook to save his own brother from Gre'Thor, B'Elanna convinces Janeway to allow herself to be induced into a coma, in order to return to the Barge, and exchange her soul for her mother's. Then she would suddenly be revived in order for them both to escape Gre'Thor. When B'Elanna comes back to the Barge, Kortar reveals that he is aware of her attempt to save both herself and her mother by "cheating" as B'Elanna's mother puts it. He asks her whether or not she would truthfully sacrifice herself to Gre'Thor so that her mother could enter Sto-Vo-Kor. She agrees, and enters Gre'Thor, where she appears on a dimly lit version of Voyager, and it is revealed to her that her eternal punishment will be to live on a facsimile of the ship.
When B'Elanna is once again told that it was "not her time", she appears in several different scenes confronting the crew and her mother, where she finally learns that it was her uncontrolled anger that gave her such dishonor to warrant Gre'Thor. She speaks with her mother's spirit, both saying they will meet one day in Sto-Vo-Kor. B'Elanna renounces the anger that has dishonored her and comes to on the real Voyager.