A famous warrior named Achilles has his battle prize stolen from him. In revenge, he kills everything in front of him to restore his pride.
“No man or woman born, coward or brave, can shun his destiny.” -- Homer
And here's the jist: Achilles, one of the greatest warriors of all time, has his girlfriend taken away from him by another warrior. His girlfriend does not mean much to him, but his pride does. He refuses to fight anymore to show the Achaeans (his side) how much they need him. His best friend from birth, Patrocles, gets involved in the battle and is killed by Hector, leader of the Trojans (the side defending Troy). In his grief, Achilles brutally murders Hector to avenge his friend. The war is over.