Greg Heffley does not want to be the outcast. Everyone at Greg's middle school is hurrying to find a partner for a dance, and Greg is determined not to be left out. As a result, he devises a desperate scheme to find someone—anyone!—to accompany him on the big night. Greg's plans, however, go horribly wrong, and his only alternative is to attend the dance as a "group of friends" with his best friend, Rowley Jefferson, and a female classmate. However, the night is long, and anything can happen. Who will triumphantly arrive at the dance, and who will wind up as the third wheel?