Erkenbert the archdeacon sat in his tower room high above the great hall of the minster and pulled the candlestick closer to him. There were three candles in it, each of best beeswax, not stinking tallow, and the light they gave was clear. He viewed them with satisfaction as he took the goose-feather from its inkpot. What he was about to do was difficult, was laborious, and its results might be sad.

In front of him lay a confusion of scraps of vellum, written on, crossed out, written on again. Now he took his quill and a fresh, large, handsome piece. On it he wrote:

The list crept on and on. At the end he drew a line beneath the record of the minster’s unpaid rents, drew a deep breath, and began the mind-wrenching toil of adding the numbers up. “Octo et sex,” he muttered to himself, “quattuordecim. Et novo, sunt … viginta tres. Et septem.-” To assist himself he began to draw little lines on a discarded sheet, hatching them through when he completed a ten. He began also, as his finger crawled down the list, to put a little mark between the XL and the VIII, the L and the IX, to remind himself which bits were to be added and which were to be left. Finally he came to the end of his first calculation, wrote down firmly CDXLIX, and began to work his way down again with the figures he had omitted before. “Quaranta et triginta sunt septuaginta. Et quinquaginta. Centum et viginta.” The novice who decorously moved an eye round the doorway a few minutes later to see if anything was required returned in awe to his fellows.

“He is saying numbers of which I have never heard,” he reported.

“He is a marvelous man,” said one of the black monks. “God send there may be no harm in the learning of such black arts.”

“Duo milia quattuor centa nonaginta,” pronounced Erkenbert, writing it down: MMCDXC. The two figures now lay next to each other: MMCDXC and CDXLIX. After another interval of crossing and hatching, he had the answer: MMCMXXXIX. And now the real toil began. That was the sum of the failed rents for one quarter. What would this represent for a full year, if by divine punishment the scourges of God, the Vikings, were permitted to lie so long upon the backs of the suffering people of God? Many, even among arithmetici, would have taken the easier route and added the same figure up four times. But Erkenbert knew himself superior to such subterfuges. Painstakingly, he set up the complex procedure for the most difficult of all diabolic skills: multiplication in Roman numerals.

When all was done he stared at the figure, disbelievingly. Never in all his experience had he come upon such a sum. Slowly, with shaking fingers, he snuffed the candles in recognition of the growing gray light of dawn. After matins he would have to seek out the Archbishop.