There is a certain look that There is a certain look that turns PD on. Call it shock, surprise or terror. Part of it is the wide eyes, but that is not all. Some of it is the dilated pupils, but that is not quite everything either. A combination of arched eyebrows and a gaping mouth, maybe? Whatever it is that defines fear best, it is everything he is looking for from a girl. Her screams match her expression perfectly. They provide the melody while his whip plays a beat. Her pleadings are the lyrics and her suffering the song.