To open all of the secret doors in the Temple of Baa you need to do a few things. First thing first, clear out the four big open areas! This just makes it easier to run away if you need to. Now stand in the center room (the one with the small area in the center with the four doors on it). All referances to the directions are as follows :

LEFT : The enterance / exit of the temple is this way

RIGHT : Where the fireballs come from

UP : To the bath houses

DOWN : To the other chest rooms

Go DOWN first. Don't turn off the passage way at all, follow it to the dead end. Click on the statue to get a key.

Go back up this passage way (but don't go to the main room); use this key on one of the two doors there to unlock it. Go in and open the chest. There will be another key.

To UP to the bath houses; use this key on the door to the right and get another chest with another key.

Go back to the chest rooms (DOWN) and open the third door. You will find another chest with another key but this key doesn't fit the other bath house door; it is for the secret door behind the alter!

Follow the passage to the right and then follow around and up the stairs. Fight a whole lot of clerics! But whatever you do, don't touch the alter, actually don't even go near it! Once you've killed all the monsters (SAVE your game). Sneak around the wall behind the alter and open the secret door.

Step back and get the gong; and then RUN into the secret door. Follow it around (either left or right) and get on one of the ledges. Stand up there and kill all the skeletons with your bow! Becareful that none sneek down the secret passage to you. This is one big killing field!

Go back to the main room. Here you'll need to open the four doors in the center in the following order : RIGHT, LEFT, DOWN,UP (Others report UP, RIGHT, LEFT, DOWN works).

Open the chest and get the last Bath House key.

Go to the bath house, open the door and then the chest. This will give you another secret door key.

Head back to the alter room and into the secret passage. Go UP to the ledge over looking the alter room and move all the way to the LEFT. The door will be on the UP wall. In here you'll get another secret door key. This door is directly opposite you on the other ledge.

In this room you'll get the item you came looking for.

NOTE : I didn't try opening the four doors in the center before clearing out the alter room; because of the plaque that says something like it needs to be done last. But since I didn't try it you may be able to do this out of order