[mr_sir]

I was exploring the Red Mountain region a bit while I was going from one Dwemer ruin to another gathering the quest items and I came across a tomb. At the bottom of the tomb was a guy called Mastrius who looked like he was half dead lying on the floor. Anyway, so I healed him to see if I could get him to chat to me. He eventually got up and I talked to him but he had no dialogue options other than about the place you go to for Bloodmoon. Who is this guy - is he part of a quest I haven't come across? I'm assuming he is a vampire from how he looked but he didn't attack me at all like other vampires that I have stumbled across in tombs. I'm planning to do a vamp clan after I have finished the main quest as I already know how to get cured again thanks to my mages quests.