C390 Quincuncial Lock

"Plum Blossom Lock?" Wyvern confirmed that he had never heard of this lock before.

"Yes." The quincuncial lock. This is a very old method of unlocking locks. I've only heard it once. Generally, keys only have one hole, only the quincuncial lock has four holes, and each hole has a different pattern on the lock. Basically, this kind of lock is very difficult to make