It's the "Day of Honor," a time each year when a Klingon is supposed to reflect on themselves and their actions. B'Elanna is not in the mood to deal with it. She's been having a bad day. She has to work with Seven of Nine, the Borg drone who's recently come on board, and she can't stand her. She has been hostile toward her friend Tom Paris lately, because even though she likes him and wants to be closer to him, she is uncomfortable accepting gestures of friendship. To top it all off, something goes wrong in Engineering and she must eject the warp core to save the ship.
B'Elanna and Tom take a shuttle out to recover the core. A Caatati ship reaches it first, though. The aliens put a tractor beam on it and prepare to tow it away. B'Elanna warns them not to tractor the core, since doing so is dangerous and could blow them up. The Caatati try to chase them off, firing at their shuttle and causing a hull breach. B'Elanna and Tom have barely enough time to jump into spacesuits and beam themselves off the shuttle before it explodes. They float alone together in space and watch as the aliens take off with Voyager's warp core.
Voyager receives a distress call from the two lost crewmembers, who have a limited amount of oxygen in their spacesuits and need to be rescued. The ship is held up by the Caatati, who demand supplies in exchange for the warp core. The Borg-hating aliens also demand Seven of Nine.
As B'Elanna and Tom float in the vacuum of space they begin to feel woozy as their oxygen runs out. As they start to fall asleep they say goodbye to each other. B'Elanna insists she can't die without telling Tom the truth. It takes some effort to admit it. "I love you," she says.
Back on Voyager, Seven of Nine has managed to satisfy the Caatati. She builds them a Thorium generator, which will give them all the energy they need to power their ship's systems; and they are so pleased with it they give back Voyager's warp core and agree to let them keep Seven. With its propulsion back in place, the ship rushes off to rescue Tom and B'Elanna, who have fallen asleep in each other's arms.