Hamelin is a small town. The people there are unhappy because of the many rats that are giving them no peace. In fact, there are thousands of them.
The rats have sharp teeth and long tails. However, one of them, the King of the Rats, has a short tail and a small mouth. This is what is known as a "non sequitur" - it does not relate to the sentence before or after, and contributes nothing. It would be better to have a sentence about what the rats are doing in people's houses.
The people are helpless and sad because they donít know how to get rid of the rats. Hence, they are looking for someone who will be able to solve their problem.[/quote]
Omit the comma after "Hence".
Otherwise it looks fine.