Gunny has another quest for you in Gray Zone Warfare. He wants you to track down someone who stole his medical supplies and return them for the Medical Detective quest.
Medical Detective | Gunny | Gray Zone Warfare GUIDE | Fast/Solo | Mission Tutorial
As with previous quests in Gray Zone Warfare, you don’t have a ton of information to go on for this one. Gunny doesn’t make it easy, but he does eventually share details about where you need to go. Luckily, you can explore all of these details in the town next to your base camp, so you don’t have to go too far, but you’ll want to be prepared.
The first thing you need to do is find the key to the doctor's office in Gray Zone Warfare. The key to the office doesn't appear in a fixed location. Instead, the only way to find it is to defeat enemy NPCs that roam around the nearest town to your base camp, which differs for each faction.
Defeat as many NPCs as necessary to drop the key. As with many items in Gray Zone Warfare, the drop rate is random, so it may take a while to find it. The key should be named after the city you're in, and if so, it'll be called Doctor's Office. Keep this safe in your inventory. It's abbreviated to the "Doc" key.