On this page of our guide to Wolfenstein: Youngblood you will find a detailed description of Laser Breach Device side mission. This task concerns reaching the title cannon and using it to unlock the underground passage to Brother 2. When you arrive at your destination, you will need to find and install a special battery.
The completion of this mission unlocks the passage to Brother 2's underworld. Take care of it before taking part in the Raid Mission: Brother 2.
Who's commissioning the mission: Talk to Jemma Atwood in the hideout in the catacombs.
Mission difficulty level: Do not proceed with this task if your sister is not at least level 15 of experience.
Use the subway network to move to Political Detention Area 4. Set the described mission to active and follow the instructions on the mini-map. It is worth noting that if you have an unlocked southern subway station in this district (Brother 2 District South Side), you will be able to reach your mission faster.
Whatever metro station you choose on your way to where the cannon is, you'll meet a very strong Zerstorer. There's no need to fight him. You can sneak past him or escape from him.
The destination is a triangular square with a parked bus with a laser gun installed on it. Deal with the surrounding Nazis. Come in and try pressing the button. You will find out that you need a battery to run the cannon.
Now you need to go to the area of Victory Boulevard. You can return to the nearest station or move to the catacombs and interact with the map again.
Once again, use the mini-map and the icon on the screen to locate your destination. A narrow alleyway between buildings should lead you to where you can find the battery. You need to reach the area shown in the picture. Take care of the neighborhood security first. Among other things, there are Robotersoldat machines to defeat - remember to use the right weapons to destroy their armor. There are also red barrels in the area that you can detonate.
After the battle, reach the blue container. The sisters must open it together. In the container you will find supplies and Laser Battery.
Head back to the Political Detention Area 4. Place the battery in the laser. You have to defend yourself while you wait for the laser to charge. Quickly throw grenades at enemies that "land" on the square.
Press the red button after receiving the info that laser is ready to use. This time it will work properly and cut the passage to the underground.
Rewards: 5500 XP, 275 silver coins, 1skill point, side mission Brother Underground 2 - take care of it for main story mission called Raid Mission: Brother 2.