Free Wagers of Sin: Time Scout II by Robert Asprin, Linda Evans

everyone except the boy who clung to his arm and groaned.
    Then the air began to groan:
    It wasn't an audible sound, but it was exactly like the painful buzzing in his skull the last time he'd been close to this warehouse. Lupus swallowed a few times and tried to find the source of the noise that wasn't exactly a noise. A hush fell over the crowd, punctuated messily by the sounds of wretchedly ill boys and a few murmured words of encouragement from their slaves. Lupus glanced at a blank stretch of wall, wondering yet again why everyone had crowded into this particular warehouse
    The wall began to shimmer. Colors scintillated wildly through the entire rainbow. Lupus gasped aloud, then controlled his involuntary reaction. A quick glance showed him that no one had noticed the sweat that had started on his brow. That was a relief, but it still took all his courage to continue looking at the pulsing spot on the wall. Captivated by the sight, he couldn't look away, not even when a dark hole appeared in the scintillating, circular rainbows, his hindbrain whispering to run! The hole widened rapidly until it had swallowed half the warehouse wall. Lupus fought back once more the instinct to run, then swallowed instead and whispered softly, "Great war-god Mars, lend me a bit of your confidence, please."
    People started stepping into it.
    They flew away so fast, it was as though they'd been catapulted by a great war machine. Someone took the other arm of the boy Lupus was "helping" and pulled him toward the gaping hole in the wall. Lupus wanted to stand rock-still, terrified of that black maw that swallowed people whole down its gullet. Then, thinking of vengeance and his carefully sharpened gladius, he drew a deep breath for courage and moved forward in the midst of the half-dozen boys who were manfully struggling to overcome their illness. Lupus hesitated on the brink, sweating and terrified-
    Then squeezed shut both eyes and stepped forward.
    He was falling ...
    Mithras! Mars! Save me
    He went to his knees against something rough and metallic. Lupus opened his eyes and found himself kneeling on a metal gridwork. The boy who had gone through with him was vomiting again. Men hauling baggage stumbled past them, struggling to get around. Lupus hauled the kid to his feet and dragged him in the direction the others had taken, down a broad, gridwork ramp. Chaos reigned at the bottom, where several other of the boys were still holding up the line, vomiting piteously all over a young woman in the most outlandish clothing Lupus had ever seen. Everyone in line was trying to slide some sort of flat, stiff vellum chip into a boxlike device, but the boys were making a mess of the entire procedure. The young woman said something that sounded exasperated and disgusted and glanced the other way
    Lupus, who had no flat, stiff vellum chip to insert into the device, slipped quietly past and fled for the nearest concealment: a curtain of hanging vines and flowering shrubs that screened a private portico. Panting slightly and cursing the fear-borne adrenalin that poured through his veins the way it did just before a fight, Lupus Mortiferus took his first look at the place where the thief who'd stolen his money had taken refuge.
    He swallowed once, very hard.
    Where am I? Olympus?
    He couldn't quite accept that explanation, despite the terrifying magic of a hole through a wall that sometimes existed and sometimes didn't. Atlantis, perhaps? No, that had been destroyed when the gods were young. If it had ever existed at all. Where, then? Rome was civilization in this world, although traders spoke of the wonders of the far, far east, from whence expensive silk came.
    Lupus didn't know the name of the cities where silk was spun into cloth, but he didn't think this was one of them. It wasn't a proper "city" at all. There was no open sky, no ground, no distant horizon or wind to rustle through treetops and evaporate sweat from his skin. The place was more like an