Son said he would come back at about 3 o'clock pm this afternoon. First, I told him to go to mother's because at that time I would be at school and elder sister might be out. But later on my way to school I changed my mind. I decided to be back in time waiting for son. With Mr. Yu's agreement, I moved forward my geography class from the seventh period to the sixth period when he should give physics lesson to the class I taught according to the schedule. So I could ask leave earlier and get home to meet son. As soon as I stepped into our apartment, the telephone rang. I took up the receiver and heard son saying he had arrived at the gate of the yard of our housing estate.