This guide shows the complete walkthrough of the “Deep Trouble” side quest in Horizon Forbidden West.
Deep Trouble quest starting location
You will get this quest by talking to Arnuf in Crimson Narrows at the location marked in the picture below.
Go to the mine & Talk to Foreman
Go to the location marked in the picture below and talk to Korvend. He will request you to rescue two missing miners.
Find the Missing Miners
Enter the mine. Then take the left path and dive into the water. Swim straight ahead through the flooded tunnel. After coming out from the first tunnel, swim through the tunnel on the right side. Swim straight ahead and you will come to an area with two miners as shown below. Talk to the miners.
Drain the Mine
After talking to the miners, turn left and dive into the water as shown below. Then swim through the tunnel. Here you will face a strong water current in the opposite direction. You will need to use Boost to get through the current. After emerging from the other side, climb up the ladder.
Go to the Mine Cart
The objective marker will now point to the Mine Cart. Dive into the water and swim towards the objective marker and then climb up the ladder as shown in the picture below to reach the platform underneath the mine cart.
Then proceed in a linear path and shortly you will reach the location shown in the picture below. Here you can proceed on the surface or swim underwater to avoid enemies.
Dive into the water and proceed ahead. After coming out from the other side, climb to the surface and follow the tracks to leave the area as shown in the second picture below.
After the end of the tracks, turn right and climb the wall ahead. Then proceed in a linear path until you reach the room with the cart. Use pullcaster on the crane ahead to make it face towards you as shown in the picture below.
Then jump on the crane and climb the scaffolding behind it to reach the mine cart. Approach the mine cart and detonate the explosives.
Return to the miners
Use pullcaster to remove the crate blocking the path as shown below. Then proceed ahead to reach the miners. Then return to Korvend to complete the quest.
