Things got out of hand and you have to help Gunny in Gray Zone Warfare. A negotiator was sent to the old bunker you found, but it turned out to be a trap. He wants you to come over and find out what happened to him.

Since the negotiator wanted to negotiate a truce, Gunny wanted you to enter the area weapon-free. You can expect to encounter multiple enemies when you visit this location in Gray Zone Warfare, and it's a good idea to bring your best gear to try and save them.

You can find the room they took the negotiator to in the bunker on the bottom floor in the second office. You can reach this location by fighting your way through the bunker after going through the Barracks. This location has several heavily guarded NPCs that you will need to fight through. Unless another team is there for you, expect a firefight as you would probably expect from various Gray Zone Warfare missions.

Unfortunately, the room you need to reach the negotiator is locked. It’s behind the second office door, and you’ll need a key. Much like other missions in Gray Zone Warfare, such as True Grit and Guns & Ammo, there’s a specific key you need to find, the Office 02 Key, which only drops NPCs. You’ll want to eliminate and search the nearby NPCs patrolling the area and hope that they drop the key for you to grab. It can take a while to find the key, as enemies don’t respawn right away.