What happens in the middle of the night? What are the results of this event?

In the middle of the night, two men sneak in through the window. When the thieves discover Mattie they threaten her life if she doesn't give them money. Thankfully, grandfather appears holding his musket. One of the men flees, and the other attacks Mattie's grandfather. In response, Mattie slashes the intruder with a sword. In the end, Grandpa dies, and Mattie is left alone.