The Lesson is presented in one act with no scene breaks or intermissions. The play opens in the professor’s home office/dining room, which looks quite ordinary. The doorbell rings and the maid, Marie, scurries in to answer it. Marie, aged 45 to 50, greets the young pupil, an 18-year-old woman who has come for a private lesson. Marie invites the pupil to sit and calls for the professor as she exits hastily. In a weak, “rather reedy” (45) voice, the professor promises his presence momentarily. The student, who “seems to be a well-brought-up girl, polite, but lively, gay, dynamic” (45) takes out a notebook as if studying. As the stage directions dictate, throughout the play, the young pupil becomes increasingly inhibited and withdrawn until she is “almost a mute and inert object in the professor’s hands” (46). The professor, aged 50 to 60, enters. He is inhibited and quiet, his timidity occasionally interrupted when “a lewd gleam comes into his eyes and is quickly repressed” (46).

Like the pupil, his demeanor changes over the course of the play as if he absorbs her liveliness, becoming aggressively confident and loud.