This quest can be started by ascending the tallest tower in Free Heap and talking to Petra. Upon arriving, Aloy meets the amicable Oseram inventor Petra Forgewoman, the leader of the settlement. A group of bandits has come between the Oseram and some valuable power cells in their foundry, and are trying to drive the Oseram off the claim. Furthermore, a pack of Scrappers have driven the Oseram away from some special weapon parts. Petra tasks Aloy with retrieving the needed goods so she can finish a powerful prototype weapon.
Aloy heads to the east of the settlement until she comes across the Oseram foundry, which is crawling with bandits. Aloy takes out all the bandits between her and the cells. There are high rock ledges and platforms all around the area that she can use to quietly snipe all the guards without raising the alarm. One is on a crate, another is at the top of a tower, and the last is in a junk heap.
Before Aloy leaves the foundry, she spots a bandit up above, who angrily yells down at her that the clan is on its way to burn Free Heap to the ground and will then come from her. He then retreats down a zip line. Aloy must head to the north to a junkyard crawling with Scrappers. Aloy searches through some scrap heaps to find the weapons parts, either killing or avoiding the few Scrappers that get in her way.
Returning to Free Heap, Aloy gives Petra the parts and warns her that a full attack is coming. Petra coolly welcomes them to try, and finishes her "dispute settler:" an extremely powerful weapon called the Oseram Cannon. Aloy then uses this deadly prototype to take out the entire clan of bandits.
Aloy returns the cannon to Petra, who is satisfied with the weapon's potential (although she admits it has room for improvement) and even more so with Aloy's help, telling her that she is in her debt.
- "The saying goes that you can only trust metal--but my trust was well placed in you. You're owed, Aloy, machine hunter. I won't forget it."
- ―Petra, at the quest's conclusion.
- Go the the Bandit Lair
- Recover the Power Cells
- Go to the Scrapper Den
- Recover the Weapon Parts
- Give Weapon Parts to Petra
- Protect Free Heap
- Talk to Petra