This guide will show you how to complete The Mountain That Fell, a main quest in Horizon Zero Dawn. Read on to learn the objectives, strategies, location, and rewards for The Mountain That Fell main quest.

The Mountain That Fell Quest Information

General Info

The Mountain That Fell Walkthrough

How to Complete

	Objectives
1	Go to the Bitter Climb. The Bitter Climb can be found in the mountains north of Free Heap. Head over to the marked Campfire to begin the quest.
2	Ascend the Bitter Climb (First Level). Climb up to the first level. Here, players will fight 3 Stalkers and a handful of Watchers. Defeat them to continue the climb.
3	Ascend the Bitter Climb (Second Level). Climb up to the second level. Here, players will fight 2 Ravagers and a handful of Glinthawks. Defeat them to continue the climb.
4	Ascend the Bitter Climb (Third Level). On the third and final level is a Stormbird. Defeat it to safely make it to the ruins of GAIA Prime.
5	Go to the Ruins of GAIA Prime. With the Stormbird defeated, start heading to the mouth of GAIA Prime's crater.
6	Climb up the Outcrop. Listen to Sylens and climb up the outcrop. This leads Aloy to Sylen's makeshift workshop.
7	Talk to Sylens and Scan Yourself at the Door. Speak to Sylens about your objectives and, once done, scan yourself at the door to unlock it..
8	Descend to the Ruins for the Master Override. Follow the waypoints to descend to the ruins. Eventually, you will rappel down to reach the bridge that connects each end of the chasm.
8.5	Grab the 5th and Last Power Cell (Optional). Before you first cross the expanse leading up to the main ruins of GAIA Prime, Aloy will need to rappel down. To get the Power Cell in this level, immediately turn around after rapelling. Climb the cliff you see (there will be handholds) and it should lead you to the area containing the 5th Power Cell.
9	Search the Ruins for the Master Override. Cross the bridge and head over to the GAIA prime ruins. Follow the waypoints through the facility, past Sobeck's quarters, and into a makeshift Shrine of some sort.
10	Examine the Shrine and View the Hologram. Use the terminal to play a Hologram recording. Watch it to know what became of Dr. Sobeck.
11	Talk to Sylens. Discuss your findings with Sylens before moving on.
12	Search for the Control Room. The control room is located on top of a flight of wrecked stairs. Make your way to it by following the waypoints.
13	Examine the Control Room and View the Hologram. Use the terminal to play a Hologram recording of what happened in the Control Room.
14	Talk to Sylens. Speak to Sylens about what you found and the events that happened so far.
15	Claim the Master Override. Claim the Master Override. It should be on the circular desk dominating the center of the Control Room.
16	Return to Sylens' Workshop. Exit the control room and turn right. Head down the steps and use the zipline to return to the mouth of GAIA Prime's Chasm. Climb up and return to Sylen's Workshop.
17	Attach the Master Override to the Lance. Once inside the workshop, speak to Sylens one last time. He will give you his lance to which you can attach the Master Override at the workbench.
17.5	Complete the Oseram Questline. If players have not completed the Oseram questline (first given by Erend during the events of The City of the Sun), they will not be able to continue on to The Looming Shadow main quest. Complete the Oseram Questline to resume Aloy's confrontation with Hades.

Tips and Strategies

Purchase a Shadow Ropecaster

During the Bitter Climb, Aloy will be facing a lot of fast-moving Machines. All of them have the ability to knock you down during the fight.

To get control of those very chaotic, drawn-out fights, purchase and equip a Shadow Ropecaster. The Tie Down mechanic will work wonders during this quest, allowing you to keep multiple Machines tied up and stunned for long periods of time.

Use Tearblast Arrows to Reveal Stalkers

Stalkers will turn invisible once they detect Aloy's presence. To prevent them from using this ability, use Tearblast Arrows to destroy the Stealth Generators located just below their shoulder blades.

Use Fire Arrows to Disable Glinthawks

During battle, Glinthawks will pepper the field with Freeze bombs, making Aloy stumble and interrupting her actions mid-animation. This is troublesome since the second level fight will be against 2 lunging Ravagers.

To momentarily disable Glinthawks, set them on fire using Fire Arrows. This prevents them from using any freeze attacks and forces them to land for a brief period of time. This should allow you to handle the Ravagers, painlessly.

Detach and Use Ravager Guns

To quickly deal with the Ravagers on the second level, hit their top-mounted cannons with Tearblast Arrows in order to detach them. After, tie down each one with a Ropecaster to prevent them from moving.

With the Ravagers disabled, pick up their detached guns and go to town on their disabled forms. A few bursts from the cannon should deal with each one effectively.

Use the Ropecaster to Tie Down the Stormbird

Hitting the Stormbird mid-flight will be very difficult. To easily deal with it and prevent it from escaping (as well as stopping majority of its Shock Attacks), use the Shadow Ropecaster to keep it grounded.

The close proximity allows you to easily take apart its armor in close range and exploit the different weaknesses it has.

Use Freeze Ammunition on the Stormbird's Freeze Canisters

Do note, before exploiting the Freeze Canisters, players will have to tear apart the armor covering them first. Use Hardpoint Arrows to make quick work of the plating.

Once exposed, use Freeze Ammunition from a Carja War Bow or Sling on the canisters. This sets off an explosion that freezes the Stormbird.

Use Freeze and Hardpoint Arrows to Deal Massive Damage

Oncce frozen, the Stormbird will take increased damage from normal arrows. Use Hardpoint Arrows on the Engine parts (located along its wings) to deal a high amount of damage within a short duration.

Keep repeating these tactics until the Stormbird is defeated and the way is clear to the GAIA Prime Ruins.

Grab the 5th Power Cell

If players have been consistently getting the Ancient Armory Power Cells, the 5th and last cell needed to obtain the Shield Weaver Outfit will be found in the Ruins of GAIA Prime.

1	After first entering the door inside Sylens' Workship, find the rappel location used to descend further into the GAIA Prime Ruins.
2	After you rappel down, turn around. There should be handholds that lead up to the cliff behind you.
3	Ascend this cliff face to arrive at the opening in the cliff.
4	Head inside and through the abandoned hallway.
5	The hall at the end will contain the 5th Power Cell. It can be looted from one of the shelves.

Horizon Zero Dawn Quests

List of Main Quest Guides

Main Quest Guides

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