X-13: Attack of the Infiltrator!

X-13: Attack of the Infiltrator! is a side quest in the Fallout: New Vegas add-on, Old World Blues. Upon completion, the player is awarded with the "Cardiac Arrest!" trophy/achievement. Part of this quest overlaps with the subsequent Project X-13.

Quick walkthrough

 * 1) Travel to the X-13 research facility.
 * 2) Recover the prototype X-13 gloves.
 * 3) Recover the prototype X-13 boots.
 * 4) Recover the prototype X-13 chest plate.
 * 5) Activate the Basic infiltration test to begin initializing the assembled stealth suit Mk II.
 * 6) Basic infiltration test: Acquire the X-13 document from the administrator's wall safe to complete stealth suit initialization.

Detailed walkthrough

 * Enter the X-13 testing facility, located near the perimeter fence to the west of the Big MT dome.
 * From the entrance door, go through the reception area into the corridor ahead. (For reference, to your right is a small room sealed with a force field; entry is not required for this quest.)
 * Turn left and explore the rooms adjoining the corridor. The three parts of the stealth suit Mk II can be found here (boots, gloves, and chest plate), along with terminals detailing the development process.
 * Once you have assembled the suit, continue along the corridor and open the door at the end, which leads you towards the testing area.
 * Your objective is the door ahead of you, across the walkway spanning the large force field.
 * Accessing the nearby terminal with the stealth suit Mk II in your inventory will unlock the door, allowing entry to the testing area.
 * If you are wearing the suit upon entry, it will comment on the test and direct your attention to the start area and test terminal below you. You can make your way down via the stairs through the doors ahead, or simply jump down into the room.
 * Activate the test terminal to start the basic infiltration test, in order to begin initializing the stealth suit.
 * You can freely explore the entire area before beginning the test. A search of the walls and desks will reveal many (currently inert) tripwire emitters used in later optional tests. With a Science or Repair skill of 50 these can be permanently disabled, or hacked (from a red laser beam to a blue, reading you as friendly; no alarms will trigger when you cross the blue beams).
 * Once you begin the test, you must make your way through the area, avoiding any patrolling robobrains. If you are detected the test will reset and you must return to the test terminal to start again.
 * Find the administrator's office and retrieve the X-13 document from the wall safe. Doing so will complete the quest and shut down all security measures. A reward will appear in the safe next to the test terminal.
 * There are several routes through the area on the lower floor to reach the safe. Alternatively, you can start the test then turn right from the test terminal and go upstairs to the observation level. Make your way to the area above the administrator's office and simply jump down to reach the safe, avoiding the security.
 * Once the Basic infiltration test is complete, the stealth suit Mk II will be upgraded (Sneak bonus increased by +10, to 25). Also note that enemy robo-scorpions will appear throughout the X-13 facility under the direction of Mobius.
 * Completing a certain amount of this quest will also begin Project X-13, allowing you to further upgrade the stealth suit Mk II.

Notable Loot

 * A Chinese Army: Special Ops Training Manual can be found on the floor in the room containing the chest plate.
 * A protonic inversal axe through a locked door (lockpick 75) in a small VR testing chamber.