"Century-" the other centurions echoed with greater or lesser audibility, depending on their experience with getting real power behind a shout that was above their normal range.

"Advance!"

Raggedly, because some men did not hear the command and responded to their comrades' motion, the legion began to stride forward. Most of the men gave a shout, and a few clashed the javelin in their right hand against their shield boss.

The three horsemen were cantering back to their fellows, the task of scouting the intermediate ground accomplished by the enemy. The war carts bounded over irregularities, hurling the half-dozen warriors in the back of each into contortions as they clung to ropes looped around frame members. The vehicles lurched awkwardly where the opposing slopes met at the valley bottom, but there was no gully there and not enough of a bog or watercourse to affect the advance of the legion.

A warrior in the back of either cart was banging a mallet against a sheet of bronze slung from a pole. The rumble of changing harmonics explained the greater thunder emanating from the enemy camp.

"Ware!" called Clodius, and the tribune skipped aside as the legion rejoined him at the rate of two paces per second.

There was a slight gap in the frontage between the Third and Fourth Centuries-inevitable because the units dressed ranks within themselves, and useful because it provided a narrow aisle in which the non-coms could scurry between the six ranks for which they were responsible. Vibulenus fell into step between the Third Century file-closer and the centurion of the Fourth, a dull-faced veteran named Vacula whom the tribune had never heard speak a word which was not an order or the response to an order.

"How many do you think there are?" Clodius asked. "Sir?"

Vibulenus was trying to position his round shield. It was lighter and easier to carry than the big oval scutum of the line troops, but a similar piece of equipment had seemed horribly inadequate against the sleet of Parthian arrows. Startled by the question, but openly delighted that someone was treating him as if he had some purpose, he squinted across the valley at the army toward which they strode.