We need to see if this is the manor. One of us should knock on the door and see if Fritz or the prince answers the door. I nominate Curf, as he would recognize either of them. If it is, have him give them the following note. If it isn't, I am sure he can think of a decent story, like arrow or muscle salesman. Or he could be looking for them to give them the note, but probably the muscle or hunter salesman.
Seal the note and don't have Curf read it unless he really wants to beforehand. We should also give a similar warning to the palace guard, but make it in such a ridiculous way they don't take it seriously until after the assassination. we also need to get ahold of Kieji and see what he got away with.
I have reason to believe that Argough will try to have Prince Belmont killed.