Ms. Mallard has a heart condition, so they told her gently that her husband was killed in a train accident.
At first she cries, but then she goes upstairs to alone. She spends time enjoying the nature outside her window. She reveals that she actually feels "free, free free!" from her husband. Without her husband she would be able to be intelligent and have her own thoughts. Her sister gets her to come downstairs. Mr. Mallard surprisingly walks through the door; he wasn't in a train crash. Mrs. Mallard dies of a heart attack. The doctor says it's from joy; but we know that she died from sadness that her husband still lives.