A king once faced a warlord leading an army both numerous and strong. His high priestess prophesied when he set out that only when royal blood was shed in battle would their allies come and victory be achieved. The king wanted to believe, but all his petty neighbors had abandoned him already, so aid from outside seemed hopeless.
He led from the front for weeks, daring the prophecy for the sake of his people, but was miraculously unscathed. As the armies maneuvered and the king's forces retreated in the face of mounting odds, the decisive battle finally came. Their backs to a swift, deep river, the king's forces prepared to make a stand. The battlefield was their most sacred ancestral site and the home of the high priestess.
She went out at dawn between the arrayed armies to consecrate the ground. An arrow arced from the enemy ranks as she started the ritual, an impossible shot from the warlord's own bow, and lodged in her chest. She fell dead on the field even as her killer ordered the charge to finish his conquest. The king watched dismayed and his troops wavered, for she was his cousin and had always been wise in counsel. At that moment there was a shriek that human throats could not make, soon followed by milling and confusion in the warlord's ranks.
The high priestesses' sacrifice, the royal blood, summoned the restless spirits of their ancestors. Spectral forms clambered out of the earth and held the invaders fast in their cold, unbreakable grip. The king understood now and went forward with his troops. Their swords passed harmlessly through the wraiths and the foe was destroyed to a man.