Why did Vodalus risk...?

I have a question for you guys, and hopefully you can offer me some insight here. I am on my umpteenth reread of TSotT, and I only just realized what a great risk Vodalus takes when he, Hildegrin, and Thea rob the grave in the necropolis. My next thought was: Why would he take such a risk? Or, for Whom? Whose corpse did they take? Obviously, they wanted a particular person's body, or else why would they go so far out of their way and (again) take such a risk? And does Thea's presence there indicate anything? Perhaps a member of her family was their target. Why else would she tag along on such a dangerous mission? Couldn't possibly be Thecla's body, as that was my first thought. Sorry, but this is driving me up the wall! Thanks to all in advance. If I come up with a good theory on the subject, I will post it, but so far I have nothing. Aaron Singleton

In the opening chapter of Shadow, Thea says something to Vodalus that Severian does not catch; Vodalus says in response, "You didn't have to come, Thea. How would it look to the others if I took none of the risks?" This reminds me of generals fighting at the front of their army. By taking the same risks as his men, he gains their respect. Vodalus is also very prideful. He does not seriously appreciate the danger of the watchmen. He disdains his earlier use of the gun, and when the watchmen are nearly upon them, gives the gun to Hildegrin, saying that Hildegrin might need it. This is despite the fact that he most desperately needs it, since he is holding off the watchmen. His pride drives him needlessly to fight them with his sword. When Severian saves him, he is repaid with a false coin. Wives of generals would come along with them on risky campaigns, so Thea coming along doesn't seem implausible, even if it is unnecessary for the task. I think the explanation of Vodalus taking the risk is Vodalus's character.

My thought is that the body is that of a particularly loyal, devoted follower, and he is there personally to secure it for use in further binding and perhaps even converting people to his side with the alzabo drug. A sufficiently powerful inherited personality may even turn a spy or double agent among the rebels to true allegiance.