As you question him further you learn that Connor is also a mage, and that Isolde is supporting her son's illegal magic studies. The mage admits that Loghain hired him to poison the Arl and then he admits that he is a Blood Mage! Wynne recognizes him apparently he was a mage in the Circle before he escaped to do his Blood Mage thing.
I knew it! Undead! After we kill them we hear a human talking it turns out we are in the dungeons! A quick inquiry reveals that the man is the mage who poisoned the Arl and he freely admits that but claims that he has had nothing to do with what came after that, and he does not know anything useful about it either. There is only one direction to head in that does not involve a strategic retreat, so I guess we have to open that door, eh? Wynne comments that at least the place does not seem to be much used whatever that means.
We end up in a hallway with a door at the other end, behind which the sounds of beasts are clearly heard.
