The story's first four paragraphs present the exposition. What information about the characters and setting is revealed here? What information is not revealed?

In the first four paragraphs, we learn that Mrs Mallard is a sickly woman with heart problem, and we see that her family is careful in breaking her the news her husband has been killed. The information that is not revealed is where her husband was traveling by train, or why he was on the train in the first place.