Roma Eterna by Robert Silverberg

home for Faustus to tell him that Prince Heraclius was heading back to the city. He had been hoping for such news. Tomorrow would be another exhausting day spent underground, then.
    He slept badly, though the little Numidian did her best to soothe his nerves.
    Â 
    This time they entered the Underworld farther to the west, between the column of Marcus Aurelius and the Temple of Isis and Sarapis. That was, bar-Heap said, the quickest way to reach the marketplace of the sorcerers, which Menandros had some particular interest in seeing.
    Diligent guide that he was, the Hebrew showed them all the notable landmarks along the way: the Whispering Gallery, where even the faintest of sounds traveled enormous distances, and the Baths of Pluto, a series of steaming thermal pools that gave off a foul sulphurous reek but nevertheless abounded in patrons even here at midday, and the River Styx nearby it, the black subterranean stream that followed a rambling course through the underground city until it emerged into the Tiber just upstream from the Cloaca Maxima, the great sewer.
    â€œTruly, the Styx?” Menandros asked, with a credulity Faustus had not expected of him.
    â€œWe call it that,” said bar-Heap. “Because it is the river of our Underworld, you see. But the true one is somewhere in your own eastern realm, I think. Here—we must turn—”
    A jagged, irregularly oval aperture in the passageway wall proved to be the entrance to the great hall that served as the sorcerers’ marketplace. Originally, so they said, it had been intended as a storage vault for the Imperial chariots, to keep them from being seized by invading barbarians. When such precautions had turned out to be unnecessary, the big room had been taken over by a swarm of sorcerers, who divided it by rows of pumice-clad arches into a collection of small low-walled chambers. An octagonal light-well, high overhead in the very center of the roof of the hall, allowed pale streams of sunlight to filter down from the street above, but most of the marketplace’s illumination came from the smoky braziers in front of each stall. These, whether by some enchantment or mere technical skill, all burned with gaudy many-hued flames, and dancing strands of violet and pale crimson and cobalt blue and brilliant emerald mingled with the more usual reds and yellows of a charcoal fire.
    The roar of commerce rose up on every side. Each of the sorcerers’ stalls had its barker, crying the merits of his master’s wares. Scarcely had the ambassador Menandrosentered the room than one of these, a fat, sweaty-faced man wearing a brocaded robe of Syrian style, spied him as a likely mark, beckoning him inward with both arms while calling out, “Eh, there, you dear little fellow: what about a love spell today, an excellent inflamer, the finest of its kind?”
    Menandros indicated interest. The barker said, “Come, then, let me show you this splendid wizardry! It attracts men to women, women to men, and makes virgins rush out of their homes to find lovers!” He reached behind him, snatched up a rolled parchment scroll, and waved it in front of Menandros’s nose. “Here, friend, here! You take a pure papyrus and write on it, with the blood of an ass, the magical words contained on this. Then you put in a hair of the woman you desire, or a snip of her clothing, or a bit of her bedsheet—acquire it however you may. And then you smear the papyrus with a bit of vinegar gum, and stick it to the wall of her house, and you will marvel! But watch that you are not struck yourself, or you may find yourself bound by the chains of love to some passing drover, or to his donkey, perhaps, or even worse! Three sesterces! Three!”
    â€œIf infallible love is to be had so cheaply,” Maximilianus said to the man, “why is it that languishing lovers hurl themselves into the river every day of the week?”
    â€œAnd also why is it that the