By itself, the revelation that the lycan clans had been colluding with Tamriel's two largest political powers was enough to surprise Do'rhajul and capture his curiosity, but even that was far eclipsed by her admission of what her allies were intending to do about Clavicus Vile. 

"Did I hear you properly? You wish to find one of Vile's relics and use ti to attack him? Directly, as in to create a portal into his realm of Oblivion and try to assault an actual Daedric Prince yourself? That is mad, insane, and you are insane for even considering it. I cannot even begin to list the number of ways that could go wrong, the least of which is death. Even assuming that you are able to somehow break through into Vile's realm, do you not realize that you could doom yourself to an eternity in Vile's clutches? If you die in his realm, and fail in your mission, then your soul will be his. At least if you die here on Nirn, your own lord can claim you for his realm." Do'rhajul protested. However, after a few seconds, his confrontational demeanor deflated. 

"But, you already knew that, didn't you? Of course you did. You are a master mage; you understand the workings of souls. But you are willing to do it anyway. Willing to take on that risk for the greater good. The greater good..." He repeated, looking away. "Even with all of that, I do not see how I could possibly helpful. As merciful and enlightened as you may be, most people are not. I know how people are, and I know that your clan will want my head. They will want their justice, and I do not deny that they deserve their justice. They will not stand for letting me live; I would not, in their position."