The garrison were now overjoyed at having, as they thought, repelled the danger,
but Scipio, who was now waiting for the fall of the tide, got ready five hundred men with ladders on the shore of the lagoon and recruited his force at the isthmus and by the gate.
Then after addressing his soldiers he gave them still more ladders than before so that the whole extent of the wall was covered with escaladers.
When the signal for attack was sounded and the assailants setting up the ladders against the wall mounted it everywhere in the most daring manner, the defenders were thrown into great confusion and became very despondent.
They had thought they were delivered from peril, and now they saw they were menaced again by a new assault.
As at the same time they had run out of ammunition and their losses were without severe as to dispirit them, they supported the assault with difficulty, but nevertheless offered a stubborn resistance.
Just when the escalading attack was at its height
the tide began to ebb and the water gradually receded from the edge of the lagoon, a strong and deep current setting in through the channel to the neighbouring sea, so that to those who were not prepared for the sight the thing appeared incredible.
But Scipio had his guides ready and bade all the men he had told off for this service enter the water and have no fear.
He indeed possessed a particular talent for inspiring confidence and sympathy in his troops when he called upon them.
Now when they obeyed and raced through the shallow water, it struck the whole army that it was the work of some god.
So that now remembering Scipio's reference to Neptune and the promise he made in his speech their courage was redoubled, and under cover of their shields they forced their way in dense order to the gate and began to try to cut down the doors with axes and hatchets.
Meanwhile those who reached the wall through the lagoon finding the battlements deserted not only set up their ladders unmolested, but ascended them and occupied the wall without striking a blow,
the defenders having been diverted to other quarters, especially to the isthmus and gate there, and having never conceived it possible that the enemy would reach the wall from the lagoon,
while above all there was such disorderly shouting and such crowding and confusion that they could neither hear nor see to any effect.
Walbank Commentary