Watch out when you confront the culprit, BTW. He's an unarmed fighter and pretty decent at it, at least when confronting a newbie straight off the boat. If you're not halfway decent with a weapon he'll leave you stunned and dead from fatigue, before he leaves you dead.
If you've only got a dagger and light armor, be sure to position yourself near the door for a quick exit so you can recover and attack again.