His father might have had doubts about the expedition, but the Vibuleni had made a very good thing out of farming taxes in the Province of Asia and weren't the people to decry military adventurism in the East. Besides, a family of their stature had a duty to the Republic, to act as exemplars for lesser folk in taking arms to Rome's glory.

The tribune's fingers caressed the bone hilt of the sword which he had learned to use so much better after he left Rome's service than he ever had before.

As for the "lessee folk," the common legionaries and the non-coms who had fought their way up from that status-so far as Vibulenus could recall, their major concern had been whether the King of Parthia drank from gold cups or hollowed jewels, and which would bring more from the merchants who trailed the army to buy its loot. After a time, they all had more pressing concerns-heat and thirst and the arrows that fell like rain-but those were not political either.

And besides, by then it was too late to matter.

"Decimus!" called the pilus prior, a hand on both Niger and Vibulenus to keep them from trying to descend dangerously farther. The cave had only a slight average slope, but descents when they came tended to be abrupt. "Marcus, Gaius. C'mon and talk for a minute so we don't fall and kill ourselves, all right? It's just me, Niger, and Gaius Vibulenus-you know he's all right. No tricks, just a little talk that can't hurt nothing."

There was a clink from the darkness, metal on metal, and a murmur of voices made ghostly and unintelligible by the acoustics of the cave. The tribune opened his mouth to call further demands, but Clodius forestalled him by touching his cheek with the hand already resting on his shoulder.

The next sound was the one they had come to hear, the scrape of hobnails on slippery rock and the muttered curses of the men climbing back up the slope.

"A bull to Hercules for this," said the tribune under his breath. Though the problem hadn't exactly been solved yet. "I don't like to think how the Commander'd react if he heard about a desertion."

They thought the first silent flash was heat lightning, but then the little Summoner floated beneath the rim of the sinkhole and the light spinning on its top threw patches of blue against the walls instead of the empty sky.

"Return at once to the ship," it called, its voice faint but recognizably speaking in the tones of the Commander. The illuminated swatches of rock grew fainter and broader as the beam's rotation slid it along more distant curves of the wall, then snapped back to brighter immediacy.

"Return at once to the ship," the Summoner ordered as it continued to descend toward the mouth of the cave.

"Helvius, wait!" the tribune cried as the faint blue reflection let him run forward down the slope. The figures he glimpsed thirty feet in front of him disappeared around a bend of the water-gouged corkscrew into the limestone. The forearm of one of the men was bandaged; the white fabric flashed like a flag charged with the dark smear of seeping blood.

"Return at once to the bzzrkl" said the Summoner as Clodius Afer drew and cut at it with a single motion and perfect timing. He was a good man with a javelin, thrust or thrown, but with a sword the pilus prior showed nothing less than artistry.

The little egg looked metallic, but it crushed like a pastry confection when Clodius caught it with his swordedge. The blue light rotating on top blinked off, but there was a bright flash of red that seemed to come through, not from, the casing of the Summoner. It crumpled to the ground, leaving behind it a glowing nimbus and a smell that combined sharpness with something that made the soldiers gag.

"It's all right, boys!" the tribune shouted, plunged into darkness with the memory of a shadowed drop-off to halt him, Ahead of him faded the clattering boots of the deserters, more familiar with the footing or more reckless. "We've shut it-"

Not sound but a light froze Vibulenus' tongue. Something drifted over the edge of the sinkhole the way the Summoner had, but this was huge and all ablaze with light as pitiless as the spear which had reached for Vibulenus' eyes when he was a frog.

"Stand where you are!" ordered Rectinus Falco in a voice amplified into thunder.

As an afterthought or a false echo from the screen of light, the Commander added, "Gaius Vibulenus Caper, Gnaeus Clodius Afer, Publius Pompilius Niger: remain where you are or you will be counted among the number of deserters and treated accordingly."

The harsh light glinted from sweat and bright metal on Vibulenus and his companions. They looked at one another because at first the lighted object was blinding. The notched edge of Clodius' sword winked. There were steaming black smears across the blade where something like tar had been carved from the belly of the Summoner.

Moving slowly, though he could not be surreptitious in the glare that bathed him, the pilus prior shifted the weapon behind him and began to wipe the steel firmly against his mail shirt to clean it. That probably wouldn't do much good, since the remains of the little device lay smoldering at his feet. Still, Clodius Afer had spent long enough in the army-and in life-to know that the best way out of an awkward situation was to deny that it had happened-even if you'd been caught with your cock rammed all the way home.

The object descended as regularly as if it were connected to a gear train instead of moving with a drifting, wind-shaken look as had the Summoners and even the water carts. The light blazed from its whole outer surface, twenty feet at least in length and broad though not particularly high sided. Because the light was so extensive, it smothered the shadows that it would have thrown if it were a point source of the same intensity. The shadings that gave life and individuality to a face, even in the bright sun, were erased. The three men looked like a flat painting of soldiers caught in the uncertainty that precedes death.

The object touched the ground, or came within a finger's breadth of touching, just outside the cave mouth. Vibulenus climbed up the path to rejoin his companions. Flow rock, limestone dissolved and redeposited by water, gleamed in opalescent beauty on the upper surfaces of the cave, but the stone had been rubbed dull generations ago wherever it was within reach of a hand.

Helvius and his companions were gone, but the red transverse crest from a centurion's helmet lay on the cave floor near the twist that carried the cavity out of sight.

Their eyes adapting (and reflections from neighboring stone surfaces) gave the Romans a view of the object, the vehicle, that had caught them. It was open-topped and held half a dozen figures-two of them from the Commander's bodyguard, unmistakable in their hulking, iron-clad bulk.

Vibulenus passed the non-coms with two further crisp steps toward the vehicle. He braced as if reporting to a consul on parade and said, "Sir! We believe that three of our fellows were cut off by the enemy and took shelter in this cave. I beg a delay of the recall order for myself and the subordinates who are here under my orders so that we can rescue men who were wounded and confused. Until the third watch, sir, if you please."

Midnight would be time enough. Ten minutes more, by Hercules, would have been enough without the Summoner's interruption.

The light dimmed abruptly. The vehicle's rounded sides still glowed brightly enough to illuminate the ground nearby with the intensity of a full moon, but the light was no longer a barrier intended to blind a marksman taking aim. Rectinus Falco got out by swinging his legs over the side.

The tribune with the Commander was dressed for parade: helmet and breastplate polished, the straps of his leather apron freshly rubbed with vermilion, and his crest combed to perfect order. He didn't look as though he had just survived a battle, and in a way he had not. Falco had accompanied the Commander during this engagement as with all those in the past.