Frustrated with his inconsiderate roommates, Sam (Matthew Broderick) takes turns occupying an apartment with Brian (Kevin Anderson), a sloppy husband-to-be, and Ellen (Annabella Sciorra), an aspiring painter. Although Sam and Ellen never meet in person, they fall for each other through romantic gestures left during their individual days in the apartment. But when Sam and Brian swap days without telling Ellen, her confusion threatens her relationship with Sam before it can truly begin.