When 16-year-old Diana Campbell is spending the summer at her family's Canadian island cabin on Rainy Lake, she meets Steven Erickson, whose family has a cabin on a nearby island. Because she is shy, lacks self-confidence, and has never had a boyfriend, she experiences extreme anxiety whenever she even thinks about spending time with him. Although he seems to enjoy being with her, Steven is private and quiet, so she is uncertain about his feelings towards her until the end of the summer. Before they say goodbye, he tells her how much he cares about her, and they share a first kiss. He is so respectful and affectionate that her anxiety changes into optimism about him and about her senior year in high school. Shortly after she returns home to Miami, however, she goes out with Bill Moore, a popular, experienced boy. On their first date, he tries to pressure her into doing things that go beyond light kissing. Her anxiety symptoms return and increase over time. Although she continues to write Steven, she becomes depressed and withdraws from dating anyone in her high school. She also stops seeing any of her friends except for Laura, her closest friend. Because her symptoms are so severe, she feels "stuck" about her ability to have a romantic relationship with any boy. She even questions whether she wants to return to Canada to see Steven again. Because of the help of her older sister and also due to Steven's funny, warm, and affectionate letters, she decides to take a chance and return to visit him in Canada that next summer. As soon as they reunite in Canada, she quickly realizes that Steven is nothing like Bill, so their reunion is joyful rather than anxious. She is surprised and delighted to see that because of his respect for her, she is no longer frozen in anxiety or "stuck at the starting line" in beginning her first romantic relationship. The book celebrates her new maturity, self-confidence, and optimism.