library, especially where the light was gloomy. One afternoon during his week of enforced toil, Brother Ambrose had sought the shelter of one of these ill-lighted and seldom-visited nooks of the building to recover certain lost hours of sleep, hours that had gone astray the night before as he sat up in his lonely cell and brooded over his wrongs. But before his drowsy head could nod off into dreams completely, his eye had chanced to notice a faded scroll that jutted forth from its fellows on the shelves. Starting to push the offender back in place, Ambrose's fingers had hesitated when he noticed the title: De Necromantiae.

Surely, thought the monk, such a book belonged on the Index. Then, it occurred to him that possibly the copy in front of him was the only one of its kind in the world, in which case not even the Holy Father could be expected to know it existed. Then, how could it be on the Index or be forbidden?

Taking advantage of this personal achievement in casuistry, Brother Ambrose promptly untied the scroll and began reading.

What he discovered there interested him very much. We do not intend to describe all of the marvels unfolded for him in that venerable mildewed manuscript, for some of the more gruesome mysteries of the supernatural world are better left unrevealed; but let it be said at least, that one chapter intrigued Brother Ambrose immensely. So much so, that he shamelessly whipped out his scissors and, nipping that section, stuck it inside his rough wool robes so he might peruse it at greater leisure within the privacy of his cell.

The chapter that evoked such delight and interest within Brother Ambrose's complicated brain was one that had been penned in the early ages of the Church by a lay-brother who had concerned himself with pagan magic. In it, he had described the fiendish habits and activities of werewolves and had actually even presented a formula. Ut Fiat Homo Lupinus it was entitled, which purported to give the secret words and ritual necessary to achieve the transformation from man to beast.

At last, the opportunity had arrived Ambrose's way to achieve his long-desired revenge on Brother Lorenzo!

Twenty-four hours had passed since the momentous discovery. The moment was at hand. Night again had settled upon the Spanish cloisters, the last bell had tolled; and all the good and hardy men were supposed to be at sound sleep on their rough iron cots. But in Brother Ambrose's chilly cell, a small candle burned—casting sickly light that produced huge flickering shadows against the whitewashed walls.

Brother Ambrose held the treasured piece of manuscript between his hands. It was difficult to make out the faded Latin; the writing was cramped and crude, and Ambrose was no scholar to boot. But like all persons of his times, he was quite well-aware of the existence of werewolves, werefoxes, and other such monsters; and he held no doubt but what the spell would work.

It was the scheming brother's plan to creep in the stealth of night down the corridor to the barred oak door of Lorenzo's own simple cell. There, he would knock; lightly enough to disturb no other sleepers, yet loud enough that the rapping would summon Brother Lorenzo from whatever wicked dreams might be festering in his own sleeping mind.

As Fray Lorenzo's naked footsteps were heard pattering across the bare floor, Ambrose would drink the bat's blood he had collected, sniff the wolfbane he had ground to ash, and pronounce the obscure Celtic words that would alter the very atoms of his flesh, transforming them into an obscene travesty of life. Brother Lorenzo, when he opened the door, would be met not by a fellow human being, but by a snarling fanged wolf that would hurl its hairy bulk at the drowsy monk's own throat.

The next day, the entire monastery would be awakened, of course, by shouts of the news that foul murder had been discovered. But no amount of detection would ever manifest the bestial murderer. Brother Ambrose would hug to his soul the secret