Modern Warfare 4 DMZ X01 & Deep Vault Guide: Hajin B0 Entrance, Executive Keycard, and Extraction
Introduced alongside the launch of Call of Duty: Modern Warfare 4 Season 1, the clandestine X01 underground facility serves as the extraction mode's high-stakes subterranean Black Site, following in the footsteps of Building 21 and the Koschei Complex. Even better for players who have yet to purchase the full game, Activision is running a DMZ Free Access event from November 6 through November 11, 2026 (ending at 10:00 AM PT) across PC (Steam and Battle.net), PlayStation 5, and Xbox Series X|S, granting full access to Hajin, Ghost Orders, and the X01 facility with full progression carryover.
Contrary to early community rumors, you do not need an access card in your backpack just to ride the surface elevator down into X01. However, cracking open the facility's heavily guarded X01 Deep Vault, surviving the lockdown alarm, and making it back out alive requires a strict sequence of keycard encoding, turret evasion, and alternative extraction routes.
How to Enter the X01 Location from Hajin (Grid B0)
There is no separate playlist queue for X01 in the main menu. Instead, you must infiltrate the underground complex directly during a standard DMZ match on the Hajin exclusion zone map. While long-range setups like our DMZ Mosin-Nagant sniper loadout excel across Hajin's open streets, make sure you pack a close-quarters secondary weapon before heading underground.
- Exact Map Coordinates (Grid B0): Deploy into Hajin and travel to the far northwestern corner of the map in sector B0, located just north of the Jayon Warehouses and the northern river road.
- Opening the Compound Gate: Locate the heavily guarded walled industrial compound near the northern border. Approach the gated entrance on the right-hand side and press the red "ENGAGE" button on the wall panel to unseal the perimeter gate.
- The Freight Elevator Airlock: Head inside the main structure and follow the corridor to the right until you reach the mesh cage of the industrial freight elevator.
- Mandatory Squad Check: Make sure every member of your squad steps completely inside the elevator cage before interacting with the interior keypad ("Hold to Enter X01"). Any teammate standing outside the cage when the prompt triggers will be left behind on the surface of Hajin while the rest of the squad transitions down to the X01 Data Center floor.
How to Get the Executive Keycard and X01 Deep Vault Key
Once your boots hit the Data Center floor inside X01, the real keycard hunt begins. Unlocking the core X01 Deep Vault requires chaining together three specific items inside the facility across a single run or multiple deployments using a Secure Bag:
- Find a Blank Keycard: Search containers, desks, and lockers throughout the X01 complex, where Blank Keycards spawn as a common RNG drop. You can also earn free Blank Keycards by completing the new Season 1 Ghost Orders.
- Program an Executive Keycard: Locate one of the Keycard Encoder Stations (3D printer terminals) inside the facility layers and use it to program your Blank Keycard into an Executive Keycard.
- Grab the Deep Vault Key in the Administrative Area: Fight your way up to the second floor of the Administrative Area, swipe your Executive Keycard to unlock the restricted loot room door, and pick up the Deep Vault Key resting on the desk. If you have a Secure Bag equipped, stow the key immediately so you do not lose it if your squad gets wiped. Note that a vault access card can also drop by hunting down and eliminating the facility's elite Captain or Lieutenant boss.
How to Unlock the X01 Deep Vault Core and Survive the Lockdown
With the Deep Vault Key secured, move quickly toward the Deep Vault sector before rival operators camp the choke points.
- Bypass the Automated Turrets: Use the Deep Vault Key to open the main sector gate. Advance carefully through the interior corridor by staying out of the sensor lights of the active automated turrets.
- Trigger the Lockdown Control: Climb the staircase leading up to the elevated Control Room and press the lockdown button on the console to initiate the core door sequence.
- Survive the Alarm Phase: Hitting the switch triggers blaring facility-wide alarms, locks down the room, and alerts both nearby player squads and heavy AI reinforcement waves. Hold the upstairs room (solo players often rely on self-revives or the Die Hard Pro perk strategy to stay downed and outlast the chaos) until the blast door down at the core finishes opening.
- Claim the Core Rewards (Argonaut Armor): Drop back down the stairs and breach the open core vault to loot restricted DRC lockers, high-value contraband, and the ultra-rare Argonaut Armor killstreak gear.
X01 & Deep Vault Walkthrough Summary Table
| Step | Sector / Location | Required Item or Action | Reward / Outcome |
|---|---|---|---|
| 1. Enter X01 | Hajin (Grid B0, north of Jayon Warehouses) | Press red "ENGAGE" wall button + group up inside Freight Elevator cage | Direct descent into X01 Data Center (no keycard needed) |
| 2. Blank Keycard | X01 Data Center / Ghost Orders | Loot facility containers or complete Ghost Orders | Acquires a Blank Keycard |
| 3. Encode Keycard | Keycard Encoder Station (3D Printer terminal) | Program the Blank Keycard at the terminal | Crafts the Executive Keycard |
| 4. Deep Vault Key | Administrative Area 2nd Floor (or Captain Boss) | Unlock restricted loot room door and check the desk | Secures the Deep Vault Key |
| 5. Breach the Core | Deep Vault Sector & Upstairs Control Room | Evade automated turret sensors + hit Lockdown Control button | Unlocks DRC lockers and the Argonaut Armor |
| 6. Safe Extraction | Deep Vault Side Shafts & Active X01 Exfils | Use "Force Open" side door on the left or vertical escape ropes | Escapes jammed elevator and extracts before facility lockdown |
How to Extract from the Deep Vault and X01 Location
Attempting to leave the Deep Vault catches many first-time squads off guard because the primary entrance elevator frequently appears unpowered or jammed after the vault sequence completes.
If the main elevator refuses to operate, immediately look for alternative egress routes: check the side doors to the left of the entry descent for a "Force Open" interaction prompt, or locate the vertical escape ropes leading up through secondary maintenance shafts to return to the upper facility decks.
Finally, keep a constant eye on the match timer. As warned in the facility's tactical briefings, X01 actively purges intruders by shutting down and sealing extraction points one by one as the clock winds down. Open your tactical map as soon as you clear the vault, ping the remaining active exfil elevators, and be ready to clear a final wave of AI defenders before the blast doors lock for good.
Born and based in Montreal's Mile End district, Maëlle "Kaelen" became close friends with Chaya during their university software engineering years, bonding over late-night coding labs, campus LANs, and World of Warcraft raids alongside Grimtag and Heimdall. A game systems balancing consultant and lifelong theorycrafter, she cut her teeth in the early 2010s writing boss walkthroughs, frame-data breakdowns, and competitive meta guides for specialized French-language MMORPG and esports portals, including Mondes Persistants, as well as North American strategy collections. On Pro-Gamer, she leads in-depth walkthroughs, build optimization, and tactical esports coverage.
