The Resident Evil 4 square lock boxes in the Castle section need a special key called a Cubic Device, and you won't be able to open them without it. It's definitely worth doing - those five square ...

As you explore the dangerous halls of the Castle, it won't be long until you stumble upon Square Lock Boxes that can only be opened with a special key known as a Cubic Device. Each of the five Square ...

To find the Square Lock Box key, you will need to follow the main story until you reach the Castle Armory. This holds a particularly difficult fight, but afterwards you’ll get the Cubic Device, which ...