The infiltration program in X-13 felt spent, having repeatedly upgraded the Stealth Suit until it could upgrade it no more. It felt warm, fulfilled, and a bit sluggish. It realized not long after, the Stealth Suit had left it without so much as a note on the nightstand.
The first section is comprised of three labs, each containing a part of the stealth suit Mk II. The second section has two levels. The top level is an observation point for researchers with a Virtual Reality stealth testing area, and the lower level is a test track for the stealth suit Mk II.
Stealth suit Mk II disassembled into three pieces and automatically added to your inventory after you have collected all 3 parts. (It has a Weight of 25 once assembled.)
As soon as you enter the facility, continue through first door, and go left down the hallway. The rooms before the end of the hallway are Labs #1, 2, and 3. One part of the armor is found in each of the lab rooms (on identical tables showing an armored man diagram).
Auto-Doc Upgrade: Implant Y-7 holotape for the Implant Y-7 stored in the terminal just left upon entering office observation area #1 (not to be confused with office observation area #2). You can find the office observation area #1 by entering the reception observation area, and going straight to the other side of the room, where you will find a door with a sign on the floor reading "office observation area #1".
There are 3 thick red paste and 2 thin red paste in the room where the player finds the prototype boots, on a table at the room's south end. This is the only place in the game thin red paste can be found without the Them's Good Eatin' perk.
X-8 kennel key in a suitcase in a room with a force field covering the door to your right upon entry.
2 Chinese Army: Special Ops Training Manuals: One is in the reward safe upon completion of all the stealth suit tests, and the other is located on the floor, opposite the door in the room where you acquire the chest plate for the sneak suit.
2 bottles of Nuka-Cola Victory: One is located underneath a chemistry set, on the first floor, before the testing lab, along with a Nuka-Cola Quartz. The other Nuka-Cola Victory is found near a hot plate in office 2 observation area.
3 battle brews in a strange cask in the night stalker area of the basement and, in the same room, by looking above where a force field can be seen, disable it with the upgraded sonic emitter.
The rare doggie treat can be found in a dog bowl where the night stalkers spawn on the lower level of the main floor.
Recipes - Lockpick skill book can be found in one of the vents in the stealth testing lab - the one over the double doors in the reception area. It is possible to reach this vent while standing on the railing in the Reception Observation Area.
Recipes - Sneak skill book From the test entrance turn right and go through the left door (the one sharing a wall with the "Hold up, Rocketeers!" poster), go through the door just on your right (the one sharing a wall with the Repconn poster), go through the hole in the wall on the right, go straight through the next hole in the wall, and the skill book is between the two fridges.
Stealth Boy to the right of a terminal with a bottle of wine, above the REPCONN managers office.
There is a LAER on the roof of the facility which is accessed by walking along the pipe joining the north wall of the building to the small cliff, start from the Big MT west tunnel's left side, near two duffle bags and go up.
Preserved meat can be found by following the tunnels in the lower area under the force field on the main floor. The still can be found in this same room.
Towards the end of the test track, there is a sewage pipe that will lead the player to a clashed room containing a Strange Still. The note on the still reads, "1 vodka, 1 mutant cave fungus, 1 Salient Green", which is the recipe for the still to make battle brew. The room also contains some battle brew in the knocked over refrigerator and a "strange keg" in the corner.
In the same area as the Strange Still, if the player lingers too long, around six invisible night stalkers can spawn in the tunnel and rooms above.
Each time the test is started, the doors are re-locked. However, there is no additional experience granted for unlocking them more than once.
The interior wall vents in the observation areas overlooking the test course are actually containers concealing loot. This includes the vents that cannot be reached from the walkways.
In Office #2 Observation Area on the wall opposite the entrance is a poster for "Love Sets Sail", starring Vera Keyes.
In the VR room where you find the Protonic Inversal Axe, it is held by a skeleton, with a note explaining why he smashed the console in front of him. It seems the VR room malfunctioned, and killed its subjects.
In the rooms where you find the preserved meat, the dolls from Point Lookout can be seen.
Among and behind the structures to the Northeast of the entrance, there are several broc flower and xander root plants.
This area is a common spot for Robo-scorpion spawns.