As the man galloped away, kicking up a thin trail of dust behind him, Cato saw some of the outriders of the enemy column turn and gesture towards the small party of Romans, but no one rode out to chase them away and for the rest of the day they rode ahead of Bannus and his men, being sure to give themselves plenty of room to escape any sudden forays by the Parthian cavalry. As night fell, the enemy column halted. They managed to find enough fuel for only a small number of fires, since firewood was scarce in the barren landscape. Cato did not permit his men to light a fire. It would be dangerous to advertise their presence so openly. Instead, he waited until it was dark, and then moved position across the front of the enemy’s line of advance, to the other flank, in case Bannus decided to try to surprise the Roman scouts who had been scrutinising his movements. Then, after his men had dismounted, and a watch had been set, Cato rolled into his blanket and tried to find a comfortable patch of ground to sleep on as the temperature dropped to a freezing chill.

At first light the next day, Macro rode out of the fort to inspect the work his men had carried out. The holes that they had been digging the previous afternoon had been completed and presented a dangerous obstacle to charging cavalry. Behind the pits was the second line of defence. The men had sown a broad perimeter with the four-pointed iron caltrops that had been brought out from the cohort’s stores.The spikes would pierce the hooves of any horse, or the boots or bare feet of any attacker who plunged heedlessly towards the Roman line, crippling them instantly. Once past the second line of defence only the ramparts of the fort would stand in their way. Macro offered a quick prayer to Fortuna and Mars asking that the enemy would not have brought many assault ladders or battering rams with them. If they had then it was a only a matter of time before the superiority of their numbers decided the result of the coming battle.