+
| 8
+ +--+--+ /
| | x
+--+--+--+
|
+-o+o-+
^
|
6--+--+o-+
o o
+ +--+--+
|
+
6 = From Ultima 6th Floor {10-70}
8 = Ultima 8th Floor {10-70}
Here is the universal key.