Sinon

In the Aeneid, he pretended to have deserted the Greeks and, as a Trojan captive, told the Trojans that the giant wooden horse the Greeks had left behind was intended as a gift to the gods to ensure their safe voyage home. He told them that the horse was made too big for the Trojans to move it into their city, because if they did they would be invincible to later Achaean invasion. His story convinced the Trojans because it included the former details as well as an explanation that he was left behind to die by the doing of Odysseus, who was his enemy. The Trojans brought the Trojan Horse into their city against the advice of Cassandra (given the gift of prophecy by Apollo, but condemned to never be believed for not returning his love) and Laocoön (because two serpents came out of the water and strangled him and his sons, which the Trojans saw as a punishment for attacking the horse with a spear). Inside the giant wooden horse were Greek soldiers, who, as night fell, disembarked from the horse and opened the city gates, thus sealing the fate of Troy.[3] He was also an Achaean spy who told the Greeks when the soldiers in the horse had begun their fight.

This scene is in neither the Iliad nor the Odyssey but is in the Aeneid; it is central to the perspective Virgil builds, in support of the actual Roman sentiment, of the Greeks as cunning, deceitful, and treacherous.

In Quintus of Smyrna, the Trojans, ready to attack the Greek camp, see smoke coming from the Greek camp and cautiously approach. When they arrive at the camp they find only Sinon alongside the Trojan Horse. The reader later finds out that it was Sinon who started the fire signal that drew the Trojans to the Greek camp.[4] The rest of the camp is deserted. The Trojans circle him and gently ask him questions but when he does not answer they grow angry and begin to threaten to stab him. When he still does not answer, the Trojans cut off his ears and nose. Finally he tells them that the Greeks have fled and they built the Trojan Horse to honor Athena. Sinon claims that Odysseus wanted to sacrifice him but he managed to escape and hide in a marsh. When they gave up looking for him and left he returned to the Trojan Horse. Sinon claims that the Greeks stopped looking for him out of respect for Zeus. All the Trojans believe this story, except Laocoön who, along with his two sons, is promptly attacked by a giant sea serpent. Following this, believing that Laocoön was attacked because he offended the gods, the rest of the Trojans begin to believe Sinon's story. Feeling bad for Sinon, and fearing wrath from the gods, the Trojans bring Sinon and the Trojan Horse into Troy.[5]