Titus Livius (Livy), The History of Rome, Book 34
Evan T. Sage, Ph.D. Professor of Latin and Head of the Department of Classics in the University of Pittsburgh, Ed.

61. When he had brought the king around to this opinion, and thought that he should prepare the minds of his countrymen for what he was going to do, he did not dare to write a letter lest, if intercepted by any chance, it reveal his designs; [2] he found at Ephesus a Tyrian, Aristo by name, and having tested his resourcefulness on less important errands, he loaded him with gifts and also with the hope of rewards, to which even the king finally gave his assent, and sent him to Carthage with his instructions. [3] He gave him the names of the persons whom he needed to meet, and provided him with secret modes of identification, by means of which they could be assured that the instructions were from him. [4] When this Aristo arrived in Carthage, his reason for coming was discovered as quickly by the enemies of Hannibal as by his friends. [5] And at first the incident was discussed in conversations at social gatherings and at dinners; [6] later, in the senate some said that nothing had been accomplished by the exile of Hannibal if, even when away, he could plot revolution and by stirring up men's minds disturb the security of the state; [7] a [p. 573]certain Aristo, a stranger from Tyre, had come¹ equipped with instructions from Hannibal and King Antiochus; every day certain individuals had secret conferences with him; schemes were being concocted in secret which would presently break out in the ruin of the entire community. [8] All exclaimed that Aristo ought to be summoned and asked why he had come, and if he gave no good explanation, he should be sent to Rome in charge of ambassadors; they had already suffered enough punishment for the rashness of one man; private citizens might do wrong at their own risk, but the state should be saved not only from doing wrong but also from the reputation of doing wrong. [9] Aristo when summoned defended himself and made use of the strongest argument for his innocence, that he had brought no written communication to anyone; [10] but he did not make entirely clear the reason why he had come, and was most noticeably at a loss when they charged him with having relations only with men of the Barcine faction.² [11] A violent debate then began, some arguing that he should be at once arrested as a spy and held under guard, others saying that there was no cause for measures that suggested martial law; [12] it set a bad precedent to arrest strangers with no convincing proof, and the same treatment would be applied to Carthaginians, not only in Tyre but in other markets which they frequently visited. [13] A decision was not reached that day. [14] Aristo, employing Carthaginian artifice against Carthaginians, as soon as it was dusk hung a written tablet over the place where the magistrates daily held their sessions, in the most crowded part of the city, and in the third watch went on board his ship and escaped. The next day, [p. 575]when the sufetes³ took their seats to administer⁴ justice, the tablet was seen, taken down, and read. [15] Its message was that Aristo had come with a private message for no man, but with a public errand to the elders —so they call their senate. The charge having thus been made general, the investigation of a few men was less vigorously pushed; [16] nevertheless, it was voted that an embassy should be sent to Rome to report the whole affair to the consuls and the senate, and at the same time to complain about the injuries inflicted by Masinissa.