Enotes has a very comprehensive summary for each of the three sections in the book. Check out the links referenced below!
Also, the site also has some very valuable material to help you understand characters, themes, and other elements of the book. Refer to this link for more options:
Be sure to read as much of the book itself as you can, though. Summaries, no matter how complete, can never match up to the actual text!
What word in the first line shows the fearfulness of the incident being related?