Through your journeys in Horizon Forbidden West, you will have optional Side Quests you can complete for more experience and items. Some are simple, some more complicated, but all are worth the time and effort. Any spot with a question mark on the map has the potential to be a Side Quest, and anyone with an exclamation point over their head will most likely provide a Side Quest.
One Side Quest early in the game, once Aloy sets for the Forbidden West, is Deep Trouble. A couple miners are trapped after an erroneous detonation caused flooding. You are tasked with rescuing them from the mine.
Read below for step-by-step instructions on completing Deep Trouble.
How to free the miners
When you arrive at the mine, to the northwest of the map, speak to Korvud. He’ll inform you of what happened. You tell him you’ll save the miners, so proceed inside to begin the Side Quest.
Note that there are a number of machines near the area of the mine. Do your best to approach the mine without alerting the machines or they will seek your death.
You will be doing a lot of swimming in this Side Quest. Remember, to swim faster, push L3. To dive, press Square. To surface, hit X. Your air bar is on the bottom in blue and beware that it drains rather quickly. You can speed up your dives and surfacing with L3 as well.
Swim through a bit, diving and surfacing when necessary, to run into the two miners. One is hurt enough to be unable to move without pain. He reacts with apoplectic shock when you ask for more explosives and the other miner hands you fuses after informing you some explosives are still deeper in the mine.
You’ll need to swim some more, going through a rather long underwater tunnel before reaching the next area. Some of the caches on the floor of the flooded mine are reachable, but keep an eye on your air. Also, there is a barred passage you cannot access without a special tool and some items that are too deep for you to reach; remember all this for later in the game.
You’ll then drop into an area that has three Burrowers prowling the area. Aloy says maybe she can swim around them, so you do have options: take them out in battle with no areas to hide, swim under and around them, or both (which is what happened during playthrough). However, you can shoot those weird mushroom things to emit a stealth smoke if you want to face them. Everyone could always use more scraps and components, right?
Follow the path, climbing and advancing. You’ll come to a ledge with a ladder you can kick down; do so in case you fall. Next, use the Pullcaster (L2 + Triangle, then R2 and hold) to pull the crane toward you. The jump is a little tricky because of the angle, but make it and leap up to the tracks as pictured.
From there, approach the cart of bombs at the end of the tracks and interact with them to trigger a cutscene. Aloy lights the fuses and pushes the cart off just before they explode. It creates an opening for the water to filter out, clearing the flooding.
Now, jump down, but be ready as three Scroungers appear from under the water. Take them out and head toward the destination marker. Your path will be blocked by two boxes. Luckily, they can be pulled with the Pullcaster. Do so with one to open your path conveniently back to the trapped miners after a slight bit of climbing. Talk to them, then leave the mine and talk to Korvud to complete the Side Quest.
Deep Trouble has a bit of everything in a Side Quest. There are trapped people, some fighting, some puzzles, and of course, exploring. Now you know how to complete Deep Trouble for a nice experience reward.