The Keep Out Mission objective in MW4 DMZ is to retrieve a Lieutenant’s Key. Although this may seem easy, it may take some time because locating the key could be difficult. Thankfully, there’s an easy trick you can use to complete the challenge without losing your key, and also find the room where the key can be used.
How To Complete The Keep Out Mission Challenge
Your first order of business is to collect the Lieutenant Key. Unlike other keys in the game, this key in particular can’t be found while scavenging loot crates or other areas, but rather, as a boss drop. For this, you need to find and defeat any lieutenant that you encounter and fight them for the chance drop. This is also the first and second objective of the Keep Out mission, where you need to fight three lieutenants and get the lieutenant key. So you can complete two tasks in one go this way.
If you still didn’t get your hands on the key, obtaining the Roze’s Highrise Armoury Key also works. In this case, you need to complete Operation Grid Assault in DMZ to get the key as a sure drop. Once you get the key, place it into your Secure Backpack during exfiling so you don’t risk losing it, and also enter a match with the key in the Secure Backpack too. To equip the key, you can just drop it to the floor and pick it up to use it.
Enter a Lieutenant’s Room
There are no fixed rooms that require the Lieutenant’s Key, so you can try any bunker door to see if the key works there. The best place to use the Lieutenant’s Key is to unlock the Supreme Leader’s Bunker in the basement of the Chang-san Air Base. You can also use the key to unlock any commander or leader bunkers anywhere else. Since the Lieutenant Key has a better drop rate than other keys in MW4 DMZ, you can collect a few of them and hand them over to your teammates to unlock several different doors for various loot.
