
Pick up the phone and listen to the ranting for a bit.
DEAD CELLS KEY IN PRISON ROOFTOPS CODE
Put the files in that drawer to open a secret room that contains another enigma code (1/6) Enigma Code. You will see some papers laying on the file cabinets, pick these up, and go back to the front of the room and notice the file cabinet that has an open drawer, next to the chalkboard with the basic math on it. Ignore the phone that is ringing for now and go to the back right corner of the room. Once they are dead, go back into the room with the Nazi flags.

Finally the painted corridor will have a side door that leads to a shower room. This one is being painted, and it has a lot of curtains and supplies laying around. Please note that on the opposite side of this room is another corridor parallel to the one you just came from. This room contains several enemies that you can both take out stealthy if you are fast enough. Stab this guy in the neck and enter the room with the Nazi flags and computers. You will jump over an alley to another room, where you will already be able to see a nazi patrolling on the other side of the window you need to go through. You guessed it correctly that is a collectible that you wish to pick up so cut that box open (2/4) Gold Frame. In this room you are prompted to interact with the window but before you do, you should once again look to your right hand side and notice another fenced box that contains a golden picture frame. Once you cut through it, cut the fence on the left as well so you are now behind the steel door. There is another fence here next to the door with the steel bars. When you stand in front of the charging unit, look to your right. The lasercutter can charge itself up to a very minimal amount of battery power so you will never have to backtrack in order to proceed in the game. These are charging units for your lasercutter, so whenever you have exhausted its battery, be sure to charge it. Walk up the stairs, and you will notice that there is a yellow device on the wall. Cut a hole in the fence here between the two ladders to pick up your 2nd collectible of this mission (1/4) Gold Plate.

You will notice that there is a fenced box on your right hand side with 2 steel ladders next to it. When you walk out of this storage room to the point where you just dropped into the section through the hatch, you should take a right turn. The lasercutter allows you to cut straight through metal fences and thin pieces of metal.
