"we'll need some kind of Trojan horse"

the Trojan horse which appeared in the movie Troy, now in the town of Çanakkale near Troy.
Creative Commons Attribution Share Alikethe Trojan horse which appeared in the movie Troy, now in the town of Çanakkale near Troy. - Credit: QuartierLatin1968, Flickr
The Trojan Horse was a tale told in Virgil's Latin epic poem The Aeneid. It was the stratagem that finally allowed the Greeks to take over  the city of Troy. After a fruitless 10-year siege of Troy the Greeks built a huge figure of a horse, and a select force of 30 men hid inside. The Greeks pretended to sail away, and the Trojans pulled the Horse into their city to keep it as a victory trophy. That night the Greek force crept out of the Horse and opened the gates for the rest of the Greek army, which had secretly sailed back during the night. The Greek army entered and destroyed the city of Troy, decisively ending the war.

A "Trojan Horse" has come to mean any trick that causes a target to invite a foe into a securely protected bastion or place.