Here the two generals exerted their sagacity, the one in effecting, the other in guarding against, a deception.
Hannibal got possession of the ring of Marcellus, together with his body.

Crispinus, fearing lest any artifice should be practised by the Carthaginian's employing this signet as the means of deception, had sent round messengers to the neighbouring states, informing them, that "his colleague had been slain, and that the enemy were in possession of his seal, and that they must not give credit to any letters written in the name of Marcellus." This message of the consul arrived at Salapia a little before a letter was brought from Hannibal, written in the name of Marcellus, to the effect, that "he should come to Salapia on the night which followed that day; that the soldiers in the garrison should hold themselves in readiness, in case he might want to employ them on any service." The Salapians were aware of the fraud, and concluding that an opportunity for punishing them was sought by Hannibal, from resentment, not only on account of their defection, but also because they slew his horsemen, sent his messenger, who was a deserter from the Romans, back again, in order that the soldiers might do what was thought necessary, without his being privy to it, and then placed the townsmen in parties to keep guard along the walls, and in convenient parts of the city.

The guards and watches they formed with extraordinary care for that night, and on each side of the gate at which they supposed the enemy would come, they opposed to them the choicest of the troops in the garrison.

About the fourth watch, Hannibal approached the city.

His vanguard was composed of Roman deserters, with Roman arms.