An alien woman named Kellin (Virginia Madsen) requests asylum aboard the Federation starship Voyager. When she comes aboard, The Doctor attempts to scan her but his tricorder does not retain any data about her. She is from a race called the Ramura, whose chemistry is such that any other race fails to remember them after a few hours, and that her race is "impervious" to technologies such as tricorders. They release a pheromone that does this. She claims that she came aboard Voyager a month ago to track down a Ramuran fugitive, and that during that time she and Voyager's First Officer, Chakotay, fell in love. The crew looks into it and evidence seems to support her claim that she was on Voyager. Chakotay does not remember her, but as they work together he understands that he could have developed feelings for her.
Just as Chakotay and Kellin start to pick up where they left off, another member of her race appears and fires a weapon at her. The effect of the weapon is to disintegrate her memories of her experiences aboard Voyager. This time, Chakotay is the one trying to convince her that they fell in love, but she is unresponsive and wants to return home. Kellin and the other Ramuran eventually depart Voyager, telling Chakotay that it would be better if he just forgot about her. Chakotay wants to remember everything about this experience, and as they've loaded a virus into the computer which will erase all record of the aliens' existence and encounter with Voyager, he records events with an old-fashioned pen and paper.