[2] Nearer to the enemy's camp was a river, not very large, from which both parties supplied themselves with water; and that this might be done with safety, guards were stationed on each bank. On the Roman side were two cohorts, a Marrucinian and a Pelignian, with two troops of Samnite horse, commanded by a lieutenant general, Marcus Sergius Silus; and in the front of the camp
there was posted another guard, under Caius Cluvius, lieutenant-general, composed of three cohorts, a Firmian, a Vestinian, and a Cremonian; besides two troops of horse, a Placentine and an Aesernian. While there was quiet at the river, neither party making an attack; about the ninth hour, a horse, breaking loose from those who had the care of him, ran off towards the farther bank, and three Roman soldiers followed him through the water, which was about as high as their knees. At the same time two Thracians endeavoured to bring the horse from the middle of the channel to their own bank; but one of these having been slain, and the horse having been recovered, they retired to their post. On the enemy's bank there was a body of eight hundred Thracians, of whom a few, at first enraged at their countryman being killed before their eyes, crossed the river in pursuit of his slayers; in a little time some more, and at last all of them, and engaged with the guard which defended the bank on the Roman side. Some authors say, that by the command of Paullus, the horse was driven without a bridle to the enemy's side, and men sent to bring him back, in order that the enemy might first provoke the conflict. For when favourable auspices were not obtained by the first twenty victims, at length the haruspices declared,
that the entrails of the twenty-first portended victory to the Romans, provided they acted only upon the defensive, without striking the first blow.