(Via Flickr user Ricky Brigante/CC)

Scott Bruce helped put himself through college by working as a gravedigger. It was the 1990's in Canada, and Bruce, who's now a professor of medieval history at CU Boulder, worked at a Jewish cemetery.

"According to Jewish custom, of course, you have to be buried by sundown the day after you've died. And in a Canadian winter, that can be particularly challenging," he says, referring to the hard, frozen ground. "So I became an expert both at the shovel but also at the jackhammer."

Bruce says he didn't meet any ghosts when he worked at the cemetery, but he does believe in them. And his interest in ghosts led to his new collection, "The Penguin Book of the Undead: Fifteen Hundred Years of Supernatural Encounters." In it, Bruce collects stories of zombies and ghosts, some of which date back before Jesus' time.

He and I recently talked about the book in front of a live audience at the Newman Center at the University of Denver. During the event, some of the stories -- including the one below -- were read on stage by actor Anthony Powell, who is artistic director of "Stories on Stage" in Boulder. Hear those stories by clicking "Listen" above.

Read an excerpt:

In the thirteenth century, stories of the returning dead disseminated widely in sermons that warned medieval Christians about the eternal consequences of sin. In this story, told by a preacher named Caesarius of Heisterbach, the doomed soul of a hellbound husband visits his wife to warn her that good deeds are not enough to merit entry to Heaven. 

Not many years have elapsed since the death of a very wealthy official of the duke of Bavaria. One night the castle in which his wife was sleeping trembled so much that it seemed as though there was an earthquake. And behold the door of the chamber in which she was lying opened and her husband entered, accompanied by a giant figure, blacker than black, which pushed him by the shoulders.  

When she saw and recognized her husband, she called him to her and made him sit upon a seat at her bedside. She felt no fear, but as she was only wearing a nightgown, she draped a part of the bed covering over her shoulders, for it was cold.

She asked her husband about his condition and he responded with sadness: “I am consigned to eternal punishments.”  

Hearing this, his wife grew very frightened and asked: “What are you saying? Did you not give alms in abundance? Your door was open to every pilgrim. Do these good deeds provide no benefit to you at all?”  

He responded: “They provide no advantage at all for eternal life, the reason being that I did them out of empty glory rather than out of love.” 

When she wanted to ask him about other things, he answered abruptly: “I was allowed to appear to you, but I can linger here no longer. Behold my hellish handler stands waiting for me outside. Indeed, if the leaves of every tree were turned into tongues, they still could not describe my torments.”  

After this, he was summoned and driven away; the entire castle trembled as before at his departure and his lamenting cries echoed for a long time.”

Republished from "The Penguin Book of the Undead: Fifteen Hundred Years of Supernatural Encounters," edited by Scott G. Bruce, with permission from Viking/Penguin Books. Copyright 2016 by Scott G. Bruce.