Del and Susan always looked like someone was after them.
Everywhere they went they were constantly looking over their shoulders. Waiting at the light, crossing the street, they looked behind them as if they knew someone was about to catch them.
I found myself walking behind them on an afternoon stroll. Then, every time I encountered them, the pair were clearly intent on staying as far ahead of me as possible. Each time they dodged around me to hurry ahead I was fascinated by their air of desperation.