Find the switch to open the double doors | Chapter 6: Facility Metro: LL Guide
Last update: 11 May 2016
A switch you're looking for is located on the other side of the large hall with many opponents. Start with using the stairs to get close to the central part of this location (of course, destroy all light sources along your way so you won't be notices).
You can reach the mentioned switch in many ways. In my opinion the best idea is to choose a narrow path located on the right. Start with getting close to the fuse box, thus turning off some of lamps. Watch out for the sleeping guard and do not try to interact with a radio here, not to wake him up.
During your march over side balconies you'll probably encounter two more guards. You can try to avoid them or eliminate them. Regularly destroy also lamp along your way, so you can stay in the dark.
Another possible way is to get to the destination through the central part of the hall. In this case you main problem are larger groups of enemy soldiers. But on the other hand the game let you destroy lamps over their heads without alarming them. Thanks to that you can easily attack by surprises opponents standing in the dark or just get past them.
The last option which deserves consideration is to get to the destination through sewers. The entrance to the first part of the sewers is located near the starting point. Destroy the oil lamp and watch out for the single enemy patrolling sewers - it would be good to get him from behind and kill him or knock him out.
Unfortunately the game won't allow you to get to the other side of the hall right away. After leaving the first part of sewers you have to look around the left part of current area in order to find another descent (screen above). In this case you won't encounter any more enemies.
ALL paths described above will allow you to get to the other side of the explored area. Do not hurry with getting there though, but first locate a fuse box shown on the above screen. Interact with it, thus turning off lamps in the room above of you.
Locate the stairs leading to the upper balconies and deal with a single guard patrolling this area. Turn right. Interact with a switch cutting of the power to the hall (unless you've eliminated all guards) and then use the switch which opens the double doors (screen above).