The order to capture the demi-humans was quickly issued from Winterfell Keep and spread by the knights to all the towns in Eaglehold:

All hidden demi-humans must be uncovered within three days. Anyone who refuses to hand them over will be killed without mercy upon discovery.

To ensure the slave masters obediently hand over the demi-humans, Sylvie also agreed to purchase them at a price of 20 silver coins each, to prevent some slave masters from harboring them out of luck.

If the demi-humans were deceived by the Holy See into entering Winter's End Town, it would only increase the power of the Holy See.