That's when the magic happened. The train was approaching Harvard Square, and as it did so this girl, this crazy shoe destroying girl, shuffled her feet a little on the floor. She went en pointe--did anyone else notice? Maybe not. They were so preoccupied themselves, and she was only about 5'3" to begin with, not tall even on her toes--and she leaned sideways, away from me, supporting herself with one hand on a railing. Her feet were turned out, her toes touching each other. She held her head up, concentrating. The train slowed and then stopped, with a little jolt of deceleration that threw her away from the rail and left her--falling?--no, balanced perfectly, a tiny smile on her face, her body tense. She turned her hands outward a little, presenting this thing to herself, and then was motionless--a vertical line of a girl to whom the train and her body were the same, were mathematics, were the perfect dance. I still can see her standing that way as the doors opened in front of her, the people behind her crowding restively, wanting her to move, wanting to leave the train.