While Lauren is out of town attending a psychology conference, Alex begins teaching a freshman seminar in economics at Leland College. As he begins his first lecture, he is interrupted by a late arrival, music major Marty Brodie, a rather scattered young woman.
When she disrupts his class twice more, first with a blast of classical music from her tape player and then with a muffled sob, Alex dismisses the class early and awkwardly attempts to determine what's wrong. Admitting that she's had a terrible week during which she broke up with her boyfriend. Marty also confesses that she's terrible in economics and convinces Alex to tutor her for $15 an hour.
When Alex arrives at Marty's dorm room for their first lesson, he tries to divert her attention away from her piano. Unable to get excited about the concept of supply and demand, Marty soon teaches an enthusiastic Alex the basic melody line to Gershwin's "S'Wonderful" on the piano, then joins in with a brilliant accompaniment.
Fascinated by each other, the two end up spending a great deal of time together until Alex realizes that his feelings for Marty are beginning to threaten his relationship with Lauren. Things become even more complicated when Alex presents Marty with a piano shaped music box and their mutual attraction draws them into a spontaneous kiss.