OH NO!!!! There was a fog coming from the infamous bog, the great Grimpen Mire.
Watson and Sherlock were watching from behind a rock.
"Its's moving towards us, Watson"
Sherlock shot the hound in the hip, and the hound was dead
In the end, they found Mrs. Stapleton, and she told them where Mr. Stapleton would be. She said he would hide in the great Grimpen Mire, but he was nowhere to be seen. they assumed the infamous bog, had swallowed him.