What does Shota tell Richard and Kahlan about the veil and what do they decide to do?

Shota tells them that no one living can help Richard and Kahlan understand how to close the veil, so Richard and Kahlan decide they will have to call on the dead to find out. Richard tells the Mud People that he wishes to call the ancestor spirits and a bird falls from the sky. This is taken as a warning to not call upon the spirits, but Richard insists it is the only way.