Horizon Forbidden West: Forbidden Legacy - Alva's quest, walkthrough (2024)

This page of the Horizon 2 Forbidden West game guide contains a walkthrough of the Forbidden Legacy side quest. This is a personal quest commissioned by your companion, Alva. The following guide explains how to start Alva's quest, where to meet Alva in the San Francisco ruins, how to defeat the Slitherfang, how to reach the Atbay headquarters in the skyscraper, how to solve the two puzzles involving locked door codes, how to get to the Ancestor's office at the top of the skyscraper, how to obtain data on Leviathan, and more.

• Quest rewards
• Unlocking the quest
• Go to Legacy's Landfall
• Follow Alva to the research facility
• Kill the Slitherfang
• Follow Alva to the Atbay headquarters
• Jump to the tower
• Unlock the door - the first door code puzzle
• Climb up to the Ancestor's office
• Unlock the door - the second door code puzzle
• Search the office for the data on Leviathan

Quest rewards

1. 9750 XP
2. 3 skill points
3. Utaru Protector outfit - you need to pick it up from Alva after completing the quest; it's a very rare Survivor outfit, which, among other things, provides additional protection for Aloy at low health and increases the effects of potions
4. Recovered Alva's Data trophy

Unlocking the quest

Alva will give you this quest. You'll be able to start it once you've unlocked the GEMINI main quest. While in the Base, you should notice a green exclamation mark in Alva's room indicating an available side quest.

Chat with Alva and offer to help her solve her problem (the right dialogue option on the above screenshot). This will initiate Alva's personal quest to return to San Francisco and obtain data that will help Quen.

The recommended level for this quest is 30 and it's in your best interest to be at or around that level, as the quest involves one especially tough battle, among other things.

Go to Legacy's Landfall

Head to the Legacy's Landfall settlement neighbouring the San Francisco ruins, which you visited for the first time in the Faro's Tomb main quest.

Once there, interact with the campfire to contact Alva and summon her to this location. This will trigger a conversation involving Alva as well as Nirik.

Follow Alva to the research facility

Follow Alva. You will reach the ruins by the water, where you'll be given the task to search them. This objective will soon be updated, as a Slitherfang appears in the ruins.

Kill the Slitherfang

You've already had the chance to face the giant mechanical snake twice in the main storyline, but having obtained new weapons and outfits, you have more ways to prepare for the battle. As a reminder, the boss is weak to fire, frost, and plasma. When it comes to your outfit, opt for one that is strong against shock and acid.

During the battle against the Slitherfang, stay on the move and use the nearby ruins to hide from the big snake's ranged attacks. Remember, however, that the Slitherfang can charge and break through most objects - always be ready to jump aside or backwards.

Use the right type of ammo and target the Slitherfang's weak spots (including the spot below its mouth when it's upright). If you manage to knock the snake down, quickly run up to it to land 1-2 critical strikes.

After winning the battle, collect the loot and resume searching the ruins. Seek out the grid from the screenshot above - it's the southwest part of the indicated search area.

Jump into the water to reach the inside of the building. Keep grabbing on to the yellow ledges to eventually reach the damaged level with the interactive console.

Follow Alva to the Atbay headquarters

Your destination is an office in one of the tallest skyscrapers in the San Francisco ruins. Follow Alva and after approaching the new building, locate the yellow ledges to reach the higher level. At the location from the screenshot, you need to use the Pullcaster on the large section of the wall.

You will end up in the shaft, where you need to reach more yellow ledges. As you climb, you will need to use the Pullcaster again, this time on the vertical piece pictured in the screenshot. This will bring it to a horizontal position.

A little further on, use your bow to hit the red handle on the ladder and make it drop down.

On the new rock ledge, you will encounter some Glinthawks - you can easily dispose of these machines with silent strikes. Avoiding them is also an option.

After eliminating of or going past the birds, check out the next wall of the building with yellow points that will allow you to continue climbing.

Jump to the tower

You will eventually reach the barricaded entrance to the skyscraper. Here, you need to use the Pullcaster and target the interactive hooks.

After getting rid of the scrap metal that was blocking the passage, jump towards the skyscraper. Turn towards Alva to have her successfully copy Aloy's jump and join the main character.

Unlock the door - the first door code puzzle

Shortly after you start exploring the skyscraper, you will come across a locked door. To open it, you have to solve a simple puzzle. The nearby collectible, which you can scan in focus mode, hints at the door's code.

From the message, you will learn that the door code is a date, specifically Atbay's founding month and year. The code is 102023 (October 2023).

Climb up to the Ancestor's office

Just behind the door, you will find the first campfire. Saving the game is a good idea, as Aloy will need to face a longer climbing section during which it's easy to die.

Start by using the Pullcaster on the damaged section of wall (screenshot). Return outside and start by jumping on the metal beams sticking out of the wall of the building.

Turn toward the wall of the skyscraper and, using focus mode, locate more of the yellow climbing-related elements.

The climbing part is very linear, although it has a few more complicated activities sprinkled in now and then. The first such activity involves pulling the grid pictured in the screenshot. This will let you jump towards it and grab the handle that's behind it mid-jump.

During the climbing section, at certain points you will need to press square to allow Aloy to jump backwards.

On one of the higher ledges, you should use the Pullcaster on the easy-to-miss section of the building's wall - it's pictured in the attached screenshot. This will allow you to continue climbing once you have brought the item you grabbed back to level.

The next challenging part of the climb is pictured in the attached screenshot - Aloy has to make a backwards jump while grabbing the handle mid-jump. Continue this strategy to grab on to the following handles above.

After climbing up to the new floor, go to the location that involves using the Igniter to destroy the red flowers. This will unlock the elevator shaft, where more yellow ledges await. Meanwhile, Aloy will be joined by Alva.

Unlock the door - the second door code puzzle

You'll reach one more locked door that requires you to solve a puzzle involving the correct code. This one is more challenging and involves scanning 4 different nearby objects.

Scan the objects one at a time starting with the left one. Every time you scan an object, you will hear a comment with a part of the code. The puzzle is made more difficult, because the order of the two objects on the right is reversed - it's supposed to be 6-25 instead of 25-6.

The correct code is 402625 (40-2-6-25 obtained through subsequent scans).

Search the office for the data on Leviathan

The next quest objective is very simple. Approach the holo projector console to play Eileen Sasaki's recording.

Listen to the conversation with Alva, which will end the quest. You can optionally glide from the skyscraper at Alva's insistence. Talk to Alva again at the Base and you will receive a unique gift from her - the Utaru Protector outfit .