If you have been going around the Castle and have noticed some treasures hidden behind a Square Lock Box with a slot for a cube-like object, you might be wondering what you need to open it.

Opening the Square Lock Boxes requires that you have the Cubic Device, which is a key item that can be inserted from different angles to unlock them.

To open up the Square Lock Boxes, you will first need to get this device, which can be found somewhere in the Castle.

How To Get Cubic Device?

The Cubic Device can be found in a chest near the Armory and it’s impossible to miss it as this will be the only route you can take back to the Grand Hall.

Once you have obtained the Lion Head Statue Piece from the Armory, you will need to fight the knights before being able to exit.

This is when you can make your way back to the Grand Hall but before that happens, you will run into the chest at the end before making a turn to your left.

Cubic Device Location

The path to the Armory from the Grand Hall on the first floor is locked, which sets you off to access the Armory by going to the second floor.

After the fight with the knights in the Armory, you will be on the first floor and will be able to grab the Cubic Device and unlock the previously locked door.

This will now allow you to go back to the Grand Hall and even return to the previous parts to go back for one of the Square Lock Boxes.