(OOC Some knowledge of French wouldn't be unusual in the area. Belfort, just outside the mountains and less than 100 km to the north-east, is part of the Duchy of Burgundy. Most local servants probably wouldn't understand the language, but anyone who has travelled a bit in the region would have some a good chance of knowing some French.)
"As you know," explains Clusius, "my grandfather built a manor near Chastellion, which I inherited. Over his life, my grandfather gathered a number of odd people who were in need of a safe place to live and work. Although the valley is small, the manor itself is large and sprawling, although a bit... strange. But it would be easy to hide a few people there."
"My understanding is that the manor itself was built on lands that were granted to my grandfather and his heirs for 99 years." Clusius' tone is probably more uncertain than he wished it was, for his grasp of the legal ground of this claim is weak. "The right to collect the taxes from Chastellion, on the other hand, has to be renewed every few year by the Burgraff. Which," he points to the letter, "this does. But which is at risk should the next Burgraff decide not to renew it." (1)
Taking another deep breath, Clusius tries to switch to a slightly different subject. "The burgraff mentionned something that you may be able to clarify for me. He said my grandfather helped him... and that I could do the same for Rudolph and fix things... just like that?" He waves his hand in the air, like the Burgraff did. "Do you know what he meant? Does he really believe I can fix any problem as if by magic?" Clusius tries to instill some incredulity in that last sentence. It isn't totally faked, because he knows that many problems cannot be fixed using magic -- at least not any magic he has control over.
(1) That is essentially correct. Only the source of income is at risk, not the right to live in the covenant's small valley.