Kityn blacksmiths would create doors to protect their houses from intruders while inside, but for extra defense, kityns only put a handle on the inside of the door! This caused problems for kityns, but it defended their houses easily, so the kityns kept these one way door handles. Blacksmiths, however, began working on a project to change the kityn world forever. 12 years later, the blacksmiths invented a lock that you would attach to closed doors. Once attached, you used a key connected to the lock by a chain to unlock the door.