Flight from Zion

Flight from Zion is a main quest in the Fallout: New Vegas add-on, Honest Hearts.

This quest is received simultaneously along with "Prisoners of War", "Retake the Bridge", and "Sanctity of the Dead".

Quick walkthrough

 * 1) Fight your way to the Pine Creek Tunnel.
 * 2) Complete the three optional quests: Prisoners of War, Retake the Bridge, and Sanctity of the Dead.
 * 3) Deal with Salt-Upon-Wounds.
 * 4) Speak to Daniel.
 * 5) Use the detonator to collapse the Pine Creek tunnel.

Detailed walkthrough

 * You will start just south of the Caterpillar's Mound. Go to the Sorrows Fork Campground and, from there, head towards the East Fork Bridge. There will be White Legs hidden atop cliffs along the paths, usually in threes, so watch out for ambushes.
 * When you get close enough to Pine Creek Tunnel, the first stage of the quest will be completed. You will now have to deal with Salt-Upon-Wounds. Up the road ahead, several Sorrows tribals will engage in battle with Salt-Upon-Wounds and two or three other White Legs.
 * Daniel is here as well. It is possible for him to be knocked unconscious during the fighting.
 * Salt-Upon-Wounds will approach and initiate dialogue, stating his intent to kill the player. There are two ways to end this. You can say "Let's end this, then", and initiate combat. Or, with a Speech skill of 75 you can tell him that there's "no reason this has to end in bloodshed". He will listen to what the Courier has to say. From here, you have more options, all of which result in Salt-Upon-Wounds leaving peacefully:
 * "Your power is broken. You cannot hope to prevail here. Leave this valley in peace." Salt-Upon-Wounds leaves, but says that he will always fight and that the White Legs will remain strong warriors for Caesar.
 * "I've already crushed your warriors. Retreat now and rebuild your tribe, or die in obscurity." Salt-Upon-Wounds leaves to rebuild his tribe, promising that one day he will come back stronger than ever.
 * "Daniel and the Sorrows are weak prey, not fit for such mighty warriors." Salt-Upon-Wounds agrees with this and leaves to find more worthy opponents for his tribe to fight.
 * Once Salt-Upon-Wounds has been dealt with, speak to Daniel. He will ask if everyone has been accounted for. Saying "Yes, go!" will progress you to the next stage of the quest. If you have not completed the three side-quest missions Prisoners of War, Sanctity of the Dead, and Retake the Bridge, you will have lost your chance to do so. Joshua Graham leaves your party at this point.
 * You are given a detonator that is set to detonate the C-4 placed above the mouth of the Pine Creek Tunnel. Firing the detonator will collapse the passage and prevent any White Legs from following Daniel and the Sorrows out of Zion. Once you detonate the C4, you receive the achievement/trophy May my Hand Forget its Skill, and then the ending sequence plays.
 * If you have the "Sneering Imperialist" perk you can call Salt-Upon-Wounds "General Gobbledegook." This, of course angers him and enters combat.

Bugs

 * There is a game-freezing glitch that may occur as you attempt to leave Zion through the Southern Passage after completing this mission. While walking towards the exit that will lead you back to the Mojave Wasteland, you may be approached by a random NPC (many times a member of the Great Khans) and be handed a detonator. This will cause your HUD to disappear and your game to freeze. The only way to overcome this glitch is to restart your console.
 * The game may crash when you detonate the explosives.
 * Walking along the river with Joshua Graham can cause him to get stuck in many places.
 * Sometimes the optional quests will not show up in one's Pip-Boy.
 * Some Sorrows tribals may be left behind at the tunnel after the completion of this quest.