What Was Lost is a Side Quest in Horizon Forbidden West issued by Kotallo in the The Base after The Broken Sky, The Sea of Sands, and Seeds of the Past. You'll likely discover during Faro's Tomb. As part of our Horizon Forbidden West guide, we're going to explain everything you need to know about The Valley of the Fallen.

What Was Lost: Overview

Horizon Forbidden West: What Was Lost Guide 2
Speak to Kotallo in The Base and ask him about his personal request to start What Was Lost.
Type Description Recommended Level
Side Quest Kotallo wants to build a new arm using ancient Zenith technology. But he needs Aloy's help to complete his mission. 30

What Was Lost: Walkthrough

Return to campfire near Ninmah Research Lab from Cradle of Echoes, which is north of The Gouge. Deal with the machines outside the tunnel, including a Shellwalker. And then head to the area where Beta was and deal with the Apex Scrappers along the way. Prepare yourself because Specters will appear when you interact with the console, and can be killed using Acid damage.

Go to the second floor, splitting from Kotallo, and use the Pullcaster to get through a vent. Then, in the next room, use the Pullcaster again on the ceiling to climb up and get into a previously inaccessible room. Pry open the chest in here and loot the Zenith Components, before speaking to Kotallo and returning to The Base. This side quest will then be put on hold while Kotallo finishes building the arm.

You can continue the side quest during Singularity by speaking to Kotallo at The Base. He will tell you he wants you to help test his arm, and will encourage you to meet him at the campfire north-west of The Bulwark. Once you're there, call Kotallo and he will ask you to follow him. You'll then need to fight a Scorcher, which is susceptible to Frost damage, to complete the side quest.

Kotallo: Where Is He After Completing All Main Quests?

Horizon Forbidden West: What Was Lost Guide 10

After completing Singularity, you'll no longer find Kotallo in The Base. In order to complete What Was Lost, you can find him at the Memorial Grove, in the Throne Room where you met Chief Hekarro in The Broken Sky.

Objective Log

  • Go to the Meeting Place
  • Call Kotallo at the Campfire
  • Enter the Zenith Lab
  • Go to the Storage Room
  • Examine the Console
  • Kill the Specters
  • Find the Components
  • Give the Components to Kotallo
  • Talk to Kotallo at the Base
  • Wait for Kotallo to Finish Building the Arm
  • Talk to Kotallo
  • Go to the Meeting Place
  • Call Kotallo at the Campfire
  • Follow Kotallo
  • Talk to Kotallo
  • Kill the Scorcher

What Was Lost: Rewards

  • 9,750 XP
  • 3 Skill Points
  • 1 Shellsnapper Circulator
  • 2 Behemoth Force Loaders
  • 2 Ancient Sculptures

What Was Lost: Notes

Completing What Was Lost will unlock the Aided Kotallo Trophy.

Did you follow this walkthrough for What Was Lost? For more information on Horizon Forbidden West, including All Quests, refer to our Horizon Forbidden West guide through the link.