O Daughter of Babylon

O Daughter of Babylon is an achievement/trophy and challenge for the Fallout: New Vegas add-on, Honest Hearts.

Walkthrough
After you finish the scouting missions for Daniel, you are given a chance to side with either Joshua Graham or Daniel. Siding with Daniel and completing the subsequent quest will grant the May my Hand Forget its Skill achievement, siding with Joshua Graham and completing his quest will grant this achievement. Trudge through all of Zion, into the White Legs camp, and kill all of those you can find. Once you get to the part where you confront Salt-Upon-Wounds, Graham should have him tied down, and you have the choice of executing him then and there (with use of the Sneering Imperialist perk), or giving him a fair fight, however it is highly unlikely that he will survive.

It is also possible, through two speech checks (60 and then 90), to have Graham free Salt-Upon-Wounds and let him flee, which slightly changes the ending.

Behind the scenes

 * This achievement/trophy references the 137th Psalm of the Bible, verse 8: "O Daughter of Babylon, who art to be destroyed, happy shall he be that rewardeth thee as thou hast served us".