On this page of our guide to Wolfenstein: Youngblood you will find a detailed description of Brother 1 Underground side mission. This task concerns the passage through the underground part of the Little Berlin district. The objective is to reach Brother 1, the location of the main plot associated with one of the raids.
This mission is unlocked at the end of Lenz's Secret side mission - you can find our walkthrough description on a separate page of our guide. By going through the underground you will reach the new district of Brother 1 and be able to take on the main mission - Raid Mission: Brother 1.
As a reminder, the descent into the canals is located in the courtyard of the hospital in the Little Berlin district. After you have jumped down or climbed down the ladder, you will find a gateway to Brother 1 Underground.
It is very dark in the basement and as a result you have to help yourself with a flashlight. You can travel with a weak weapon in the other hand, or use Sturmgewehr weapon more often, which has a factory-installed flashlight.
In the initial phase of canal exploration, there is an opportunity to jump into high-pitched pipes and platforms. This will allow you to avoid some enemies or to attack them more easily by surprise.
You can try to sneak as long as you can, or you can continue to defeat enemies in face-to-face battles. If you start fighting, try to stay in better lit locations so that you don't have to help yourself with a flashlight.
Sisters need to move towards the upper sections of the underground, so look out for stairs and higher shelves on the way. You have to reach the wooden platform shown in the picture and turn left where the new stairs are located.
You don't have to explore all areas in the sewers. The destination is shown in the picture - it's the gate that sisters must lift in cooperation with each other. This will allow you to move to Brother 1 district and complete the mission.
Rewards: 4500 XP, 225 silver coins, 1 skill point, reaching the Brother 1 district.