The episode begins in the mess hall. Tom Paris and B'Elanna Torres are engaged in a conversation. Torres remarks to Paris several times that Seven of Nine is watching the two and has been in the past, but Paris dismisses her concerns, noting that Seven is writing a report. Torres eventually becomes angry and approaches Seven over Paris' objections. Seven at first claims that she is not staring at Torres and Paris, but later admits that she has been observing the couple to gain a better understanding of romantic interaction. Torres demands to see what she's written, but Seven says that she has not completed her analysis. Torres grabs her report anyway and begins reading aloud. She expresses frustration as she reads Seven's detailed chronicle of her and Paris' interactions and becomes irate and threatens Seven when she learns that Seven has even recorded instances of their "intimate relations".
In sickbay, The Doctor approaches Seven about the incident. He suggests that her interest in understanding the subtleties of human mating rituals is the result of an interest in her own sexuality and offers to teach her more about romance. She claims to not be interested in romance and says that she was only conducting a study, but he quickly points out the topic she chose and convinces her to become his student. The Doctor prepares a "lesson plan" for the former Borg with each lesson about a particular social nicety related to human romance. For example, one lesson is titled, "The First Date". Although Seven quickly masters the first lessons, her approach to romance remains stiff, businesslike, and robotic. Paris chides The Doctor for thinking that with his help Seven will eventually be able to date other crew members successfully. Nevertheless, The Doctor remains confident and makes a bet with Paris for a month's work in sickbay that she will retain a date for the entire night at an upcoming ambassador's reception.
The Doctor focuses on better understanding Seven's interests and finds that she has great musical talent. He teaches her to supplement her singing ability with emotion, and the two share a duet of "You Are My Sunshine". It is at this time that The Doctor begins to see Seven in a different light. After Seven's first date ends in disaster when she injures her partner while they are dancing, The Doctor dances with her to improve her skill, pointing out that as a hologram he cannot be physically injured. Paris eventually realizes that The Doctor has fallen in love with Seven and advises him to tell her. The Doctor is reluctant to admit his feelings, but he does ask Seven to be his date at the ambassador's reception. She agrees.
Seven behaves extremely well at the ceremony, making jokes and displaying purposeful politeness. Paris concedes the bet, but when Seven learns that The Doctor had a personal stake in asking her to accompany him to the ceremony, she storms out of the room in anger. Although The Doctor apologises and tells her that his interest was only in her development, his unresolved feelings for her plague him.
In the final scene, the audience sees The Doctor approach Seven after leaving a group of roses for her. In an emotional voice, he admits that "the last few days have been...unforgettable" and professes his love for her. However, this is soon revealed to be a holodeck simulation which The Doctor ends as he is about to be interrupted. The real Seven of Nine then approaches The Doctor and gives him an enhanced medical tricorder, saying that she remembers him expressing his desire for one and that she decided to present it to him as a gift. He is grateful, but he despairs when he learns that she has presented it to him because she wishes to end the lessons in romance because she does not find any member of the crew to be a suitable mate. In a weak and forlorn voice, he admits to her that "the past few days... have been unforgettable. Thank you." but he does not tell her of his romantic feelings. She departs, and he recreates a holodeck program that he had used for her training and plays a despondent version of George Gershwin's "Someone to Watch Over Me" at the piano.