Basically, the idea is to allow for high ranking members of a secret society to invite other nobles to join without having them travel to the guildhouse. It would work exactly the same way a priest can convert a noble with a private sermon, except with the obvious alterations. This would be a major change to secret societies especially when the two nobles are in enemy realms. What excuse could they possibly have to get to their enemy's capital, but if the two were to know where their armies were going to clash it would be that much simpler to send an invitation.
That would take A LOT of the fun out of secret societies too. In order to get this guy to join, why not have him, or help him orchestrate a legitimate reason to be in the region? Such as an attack or raid? If that noble has no kind of influence when it comes to decision making, or doesn't have such ingenuity, then how much of an asset could he be anyway?
I can still think of a few "reasons" he could get that far into your territory, for a few different classes. For example, an infiltrator attacking a lord. A trader attempting to steal food. A priest causing religious revolt. The list goes on...
Also, wouldn't there also be a fun factor in having him work exclusively for you until he CAN find a reason to be there?
