Brandon Sanderson
Chapter Fifty-Nine
TenSoon Visits Urteau
The fact that TenSoon is out of the homeland without a Contract is an important point, one I myself didn't consider up until now. Always before, anyone who wanted to hire a kandra left a message in a designated place in Luthadel. The kandra found you—a creature who was under direct Contract by the Lord Ruler to act as an intermediary.
The kandra Contract was completely confidential, even from the Lord Ruler—though he probably could have demanded to know the details of who the kandra were working for at a given time. He didn't bother, as he never thought that one would be used in a plot against him.
The kandra who arranged Contracts—a member of the Fifth Generation—would travel to the Homeland with the signed papers and the atium, and would send a new kandra out to serve the new master. Nobody left the homeland without a Contract, and if their Contract ended or their master died, then they returned immediately to the Homeland.