American Folklore

Dear Teacher,

I was reading this American folklore story but could not
understand its moral.

The Black Cat's Message

I started down the road, hoping to get home before dark since I had not brought a lantern with me. I rounded a corner and saw a group of black cats standing in the middle of the road. They were nearly invisible in the growing dark.

As I drew nearer, I saw that they were carrying a stretcher between them. I stopped and rubbed my eyes. That was impossible. When I looked again, the stretcher was still there, and there was a little dead cat lying on it.

I was astonished. It must be a trick of the light, I thought. Then one of the cats called out, "Sir, please tell Aunt Kan that Polly Grundy is dead."

One more question what is meant by " I rounded a corner" ?

Thanks