It was resolved to fight directly; and before the consuls and
praetor left the tent of Livius, the red ensign, which was the signal to
prepare for immediate action, was hoisted, and the Romans forthwith drew
up in battle array outside the camp.

Hasdrubal had been anxious to bring Livius and Porcius to battle, though
he had not judged it expedient to attack them in their lines. And now,
on hearing that the Romans offered battle, he also drew up his men and
advanced toward them. No spy or deserter had informed him of Nero's
arrival, nor had he received any direct information that he had more
than his old enemies to deal with. But as he rode forward to reconnoitre
the Roman line, he thought that their numbers seemed to have increased,
and that the armor of some of them was unusually dull and stained. He
noticed, also, that the horses of some of the cavalry appeared to be
rough and out of condition, as if they had just come from a succession
of forced marches. So also, though, owing to the precaution of Livius,
the Roman camp showed no change of size, it had not escaped the quick
ear of the Carthaginian general that the trumpet which gave the signal
to the Roman legions sounded that morning once oftener than usual, as if
directing the troops of some additional superior officer. Hasdrubal,
from his Spanish campaigns, was well acquainted with all the sounds and
signals of Roman war, and from all that he heard and saw he felt
convinced that both the Roman consuls were before him. In doubt and
difficulty as to what might have taken place between the armies of the
South, and probably hoping that Hannibal also was approaching, Hasdrubal
determined to avoid an encounter with the combined Roman forces, and to
endeavor to retreat upon Insubrian Gaul, where he would be in a friendly
country, and could endeavor to reopen his communication with his
brother. He therefore led his troops back into their camp; and as the
Romans did not venture on an assault upon his intrenchments, and
Hasdrubal did not choose to commence his retreat in their sight, the day
passed away in inaction. At the first watch of the night Hasdrubal led
his men silently out of their camp, and moved northward toward the
Metaurus, in the hope of placing that river between himself and the
Romans before his retreat was discovered. His guides betrayed him; and
having purposely led him away from the part of the river that was
fordable, they made their escape in the dark, a