What event is responsible for Maniac running away from his aunt and uncle?

When Aunt Dot and Uncle Dan show up at Jeffery’s Spring Musical they sit at opposite sides of the auditorium. As the music begins, Jeffery’s voice is normal and blends in with his fellow classmates. As the music ends, however, the crowd hears Jeffery screaming from the top riser. Maniac screams and points to his Aunt Dot and Uncle Dan. He screams, “Talk! Talk, will ya? Talk! Talk! Talk!” Abruptly, Jeffery runs out of the school and into the night. The legend of “Maniac Magee” has begun.