This floor is considered the first of the "middle floors." Floors 1 through 4 are the top floors, and floors 9 and 10 are the bottom. To be perfectly honest, there is actually no required reason to visit the middle floors. They are simply present to give party members something to explore and level up on the way to the big fight against the evil wizard Werdna. If you don't take the time to do this, you may even find the 9th floor too difficult to traverse, let alone the tenth. Interestingly, the two sequels to this game only contain six floors each.
However, if you do not take the time to succeed in the major event on Floor 4 and earn the Blue Ribbon, you will have no choice but to explore these floors since the second elevator will be inaccessible to you. Instead, you will be forced to explore every level in search of the stairs that lead all the way down to the bottom of the maze. Some expert players prefer to proceed in this fashion simply for the challenge.
This floor introduces a new feature. In the middle of the floor is an area known as the "Hall of Silence." In this area, no spell casting is allowed by your party members, inside or outside battle. You may cast spells but nothing will happen. It's as though a permanent MONTINO is cast on your party while in the area. However this does not affect enemies, who will still be able to cast spells. Also, damage cannot be healed until you exit this zone, nor can status ailments be corrected, which may leave you more vulnerable to dying than usual.
Note that the uppermost hallway of the maze is a never-ending corridor that wraps around from one side to the other.
Up Stairs (E0-N0)
These are the stairs you can take to return to Floor 4. However, you will require the STATUE of BEAR to pass through the connected hallway on the fourth floor.
Down Stairs (E8-N8)
Take these stairs down to reach Floor 6.
This is the second elevator which requires the BLUE RIBBON to make use of it. You can use it to visit floors 4 through 9.
Turn Table (E5-N5)
A single rotating floor is found on this level, and it's not much of a challenge since it is found at a T intersection, making it quite easy to figure out which new direction you are facing.
The Hall of Silence (E10-N7 - E16-N12)
Magic is sealed in this space. Even magic that you cast before you entered this section will be canceled. There are three small rooms in this hallway that you can only teleport into to investigate. Incidentally, the magic seal does not affect these small rooms.
In the Ultimate Wizardry Archives version, entering this room will disrupt all attempts at casting spells until you leave the floor. It is a long way back to the elevator or stairs, and a random encounter can quickly turn deadly when you have no ability to heal or cure poison or paralysis.