The Mud Covered Cache key is one of the tougher keys to use on all of Ashika Island in Call of Duty DMZ. While players find it as a random drop from HVTs, AI soldiers, or a supply crate like most of the other keys in DMZ, this particular key is used at the most well-guarded location on the entire map.
Players will have to travel to Tsuki Castle to use the Mud Covered Cache key. Luckily, players won’t have to dive into the center of the castle where the Tsuki Castle Hideout is, as there are dozens and dozens of Shadow Company soldiers waiting for them.
Instead, players will have to skirt the outside moat of Tsuki Castle and find a specific location where they can use the Mud Covered Cache key. There will still be plenty of guards, however, so players should come well-prepared with guns and equipment.
Using the Mud Covered Cache key in DMZ
Once you are around Tsuki Castle with the Mud Covered Cache key in your inventory, you want to head to the northeast side of the location. Here, there will be a bridge that connects the castle with the outside and goes over a small river. You will need to hop into this river and go directly underneath the bridge.
Here, you will see a crate that is submerged in the water. You can stay above water and interact with the crate, which requires the Mud Covered Cache key to open. Use your key, and you will be able to loot whatever is inside. Then, it’s probably best for you to get out of Tsuki Castle as quickly as possible, as you don’t want to die to any lingering AI enemies.