Archers on the wings of the fortress flanking the tower were shooting furiously. Some of the bolts struck the rear of the abandoned gallery, but Vibulenus and his men were protected by the wall they were assaulting. For all that, bits fell from higher up the tower as its structure warped under stress of the flames. They were not missiles as such, but a fire-wrapped scrap of battlement landed close enough to the tribune to scorch his calves, and another chunk flattened a file-closer as it rang from his helmet.

There was too much noise for the assault to be truly coordinated, but the veteran soldiers knew their jobs well enough to work without direction. Clodius and Vibulenus each levered again in quick opposition, between them prying the stone far enough for the two legionaries to drop their turf cutters and grip the block directly. Tendons stood out at the inside of Niger's elbows as the tribune stepped out of his way.

"There, by Hercules!" the legionary shouted while the block, as thick as it was high, slid out of place and crashed to the ground. It tilted as if contemplating a roll that would have put everyone nearby at risk, but it settled back with a second thud.

The legionaries had broken into rough teams, not because they were organized that way but simply because men in a tight spot look instinctively for the support of a few fellows. Another block pitched to the ground moments behind the one Clodius had attacked, though it was ten feet to the side and only incrementally helpful in weakening the structure. Aided by their initial gap, the tribune and the three men with him began to worry loose a block offset in the next layer above.

The horns and trumpets again blew the general call that would normally signal a charge. Apparently that was what Rusticanus-or the Commander?-had in mind. Legionaries protected by no more than their shields and armor began to pour over the face of the siege works fronting the tower.

Archers shot at them, but the auxiliary crossbowmen made good practice against the defenders. Without the lowering threat of the tower, archers employed by the trading guild could sweep the battlements of opponents concentrating on Roman infantry.

Vibulenus stuck his pickhead into a crevice and braced his free palm against the wall for leverage. He felt the violent shock before he heard it, fire-gnawed beams in the tower collapsing under the weight of the flagstoned top floor. Flame shot skyward in a giant version of the bellows-driven puff from the tube which had started the conflagration. Rising, wholly separated from the structure from which it sprang, a fireball expanded while its color changed from incandescent white to red as dull as that of iron quenching in blood.

"Watch it!" ordered Clodius Afer. A second stone tumbled from the wall, cracked against the first, split, and rolled to either side. Niger already had his turf cutter inserted beside the next block over and was prying so hard the thick shaft bowed.

The core of the wall was rubble, compacted between the stone facings and to an extent cemented together by time. It was not true concrete, however, and seeping rainwater had leached pockets from the material. Vibulenus chopped at it with his pick. The iron sparked but bit deep enough to crumble out a headsized chunk. Niger continued tilting his block with the help of another legionary.

Hundreds of men were joining the assault force, elbowing one another in their haste to attack the wall with their weapons. Few of them had proper tools for the job, but they did carry their sheilds. Lifted overhead by the latecomers, these provided real protection against the increasing rain of fragments as well as psychological benefit to the men concentrating on their work of destruction.

Clodius Afer was standing on stones piled at the base of the wall in order to hook out another with his pick while Niger balanced him. Every time they removed a block, the next one came easier. The crumbled mortar would have made a ram's job more difficult, because individual blocks had enough play to absorb shock without cracking or shaking the whole wall down.

Against the legionaries with picks, the structure had no protection save the weight of individual blocks. Those were no match for men with the strength and boarhound determination of Clodius Afer and his fellow volunteers. Including Gaius Vibulenus, who "Watch it!" ordered the centurion, jumping down and back as the block he was dragging teetered on one corner.

Vibulenus stepped clear and glanced around. To the left of his own little group, a thirty-foot length of facing shuddered down and outward, battering and pinning a number of the legionaries whose individual efforts had combined to something unexpectedly great. The gap rose jaggedly to a peak twenty feet up the surface, a corbelled arch sealed by the wall's rubble core.

The tremors and release from that slippage sent down not only the block Clodius was removing but three of those above it as well. "Come on, back," the tribune shouted. He bumped into a soldier who was trying to cover them both with a shield.

Feeling sudden panic at being trapped between moving rock and immobile bronze, Vibulenus slapped the legionary in the middle of the breastplate and screamed, "Back, curse you! Backl"

The shadow slicing across the ruddy inferno above them snapped the tribune's eyes upward.

The teams had released the ropes which held the hollow log poised just short of the tower battlements. That effort was unnecessary now, especially since the defenders were beginning to desert the remaining walls of the fortress in despair. A collapse of the enemy's will to fight was more devastating than a breach in his walls-but it had to be exploited immediately, and a few hundred additional legionaries boosting and dragging one another up temporarily undefended fortifications could be worth a week's grueling siege work after the defenders regained their courage.

The log struck the tower just beneath the flame-wrapped battlements and clung there. Heat threw ripples in the air and made it seem that the whole tower shook. Or else "Retreat!" the tribune said, his voice raised but his tone again that of emotionless command as his mind distanced itself from everything physically immediate.

Niger, braced by the centurion, was clambering up the pile of tumbled stone to pry loose another series of blocks. The soldier, still looking younger than the eighteen he had been when captured by the Parthians, had lost his helmet, but sweat plastered his hair to his scalp in a black cap.

Vibulenus gripped Clodius and Niger, each by an elbow. The tribune's thinking processes were too orderly and multiplex at the moment for him to be surprised that he held two strong men without strain. "The wall's about to collapse, I think," he said into the rage-distorted face of the centurion. Clodius was drunk with haste to accomplish his business, and that monomania turned to fury at anything which attempted to frustrate it.

"Get them moving," the tribune continued coolly, unconcerned that reflex had lifted the pick in Clodius' hand for a stroke to clear his arm. "Just away from the tower-don't try to climb back up the ramp. You too, Niger. Get on with it, boys."

The tone or the look in Vibulenus' eyes penetrated Clodius' mind before he recognized the tribune as a friend. He looked up, swore, and dragged the willing Niger with him toward the troops milling to the left of the gap he himself had torn.

"Get moving, ye meal-brained fuckers!" roared the centurion. "This fucker's about't' fall on our fuckin' headsl" Using his pickhandle as a cross-staff and his bellowed certainty as a goad, the squat non-com set up a motion in the troops like that of a wave sucking back from the shore over which it has swept.

Bricks blew out of embrasures midway up the face of the tower. Another floor had collapsed onto a further store of flammable liquids.