As an apprentice, one has to do some handyman tasks for the master—serving tea and water, cleaning the house, running errands, passing messages, and even helping the master with cleaning each of the ritual tools...
Among these tasks, the most important one is buying corpses.
Mr. Ghost Hayes has been training ghosts for some years, so he has a fixed source for corpses. Several clinics in town have had dealings with him, but since he's getting old and the journey from the village to town involves a long mountain road, he sends his apprentice to run the errands.
Mr. Ghost Hayes remembered clearly that the weather was bad on that day, overcast and dreary, yet the old master said this weather was good, as it deepens the resentment of little ghosts.
