Poke around the poor section of Rivertown, south of the Blue Boar inn. There are two different ways this quest can be resolved, which effect the experience reward and your reputation.
Specifically, <span class='standouttext'>Spoiler : </span><span class='spoiler'>in a basement of one of the houses you will find a bunch of meat, and can confront the guy just outside the house. If you turn him in it gives more experience, but your reputation drops.</span> (highlight the text to read)