Titus Livius (Livy), The History of Rome, Book 24
Frank Gardener Moore, Professor Emeritus in Columbia University, Ed.

24. Ready to hear and believe these charges, a daily larger multitude was flocking to Syracuse and giving not Epicydes only, but also Adranodorus, the hope of a revolution. [2] The latter was at length wearied by admonitions of his wife: that it was now the time to seize the power, while everything was confused by the new freedom not yet organized; while the soldiers one met were fattened on the king's pay; while generals sent by Hannibal and familiar with the soldiers could aid the undertaking. Accordingly he formed a plot with Themistus, whose wife was Gelo's daughter, and after a few days rashly revealed it to one Aristo, a tragic actor, to whom he had been in the habit of confiding other secrets. This man's family and station were respectable and not tarnished by his artistic profession, since among the Greeks nothing of the sort brings discredit. [3] And so thinking that the loyalty he owed to his native city took precedence, he reports the matter to the magistrates. [4] They, finding from trustworthy information that this was not unfounded, conferred with the older men, placed a guard at the doors on their advice, and when Themistus and Adranodorus had entered the senate, slew them. [5] And after the confusion resulting from an act even more terrible in appearance than in reality, since others were unaware of the reason, they at length secured silence and brought the informer into the Senate House. [6] He first told everything in order: that the conspiracy had taken its start from the marriage of Gelo's daughter Harmonia, uniting her with Themistus; [7] that African and Spanish auxiliaries had been made ready for the [p. 255]slaughter of the magistrates and other leading¹ citizens, and the announcement made that their property would be spoil for the assassins; moreover that a force of mercenaries accustomed to the orders of Adranodorus had been provided, to occupy the Island again. [8] He then set forth in detail what was to be done, and by whom, and pictured the whole conspiracy manned and armed. And to the senators indeed they appeared to have been slain with as much justice as Hieronymus. [9] But in front of the Senate House there was shouting by the mixed crowd unacquainted with the situation. Uttering wild threats, they were checked by the corpses of the conspirators before the entrance to the Senate House, in such fear that they silently followed the orderly populace to the assembly. [10] Sopater was instructed by the senate and his colleagues to speak.