Arrival at Zion

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

Quick walkthrough

 * Follow Jed Masterson.
 * (Optional) Defeat the White Legs assault.
 * Move into Zion Valley.
 * Travel to the Dead Horses Camp at Eastern Virgin.
 * Speak with Joshua Graham.

Detailed walkthrough
Once the player arrives in Zion after completing Happy Trails Expedition, a large group of White Legs will attack the expedition, killing everybody. There is no way for the player to save them, as their deaths are scripted, assuming they aren't killed by the attackers. The White Legs may come equipped with powerful weaponry, including anti-materiel rifles, 12.7mm submachine guns, riot shotguns and brush guns at higher levels and wiping them out is completely optional.

After crossing the bridge the player meets a Dead Horse scout named Follows-Chalk who can join as a companion. As the player journeys towards Dead Horse Point and Joshua Graham, Follows-Chalk will warn to stay along the path. A giant yao guai will make an appearance in a cutscene, which is the only time a guai not hostile to the player will appear.

Further along, Follows-Chalk will note a cliff with a view, which is the first opportunity to employ the companion's Well-Stacked Cairns perk. At Eastern Virgin and the camp of the Dead Horses, the player needs to enter Angel Cave and follow it until he meets Joshua Graham. Engaging in conversation with him will complete the quest.

Bugs

 * One of the White Legs might become invincible if you leave the ambush without defeating them, thus making it impossible to complete the optional part of this quest.
 * When reaching the area where the yao guai attacks, the game will crash every time, making it impossible to go further.
 * During the ambush, the White Legs may become invisible until the combat is over.
 * Some White Legs may be non-hostile and too far away from the cliff to kill them, making the optional part of the quest impossible to complete.