Thanks to these board! I found second Glowstone. By using Glowstone,I opend corridor to Venomla marmaid. I search allover these area, but I can find third tablets. Please teach me where is third tablets. Pleae!

This is where you will need 2 glowstones on you. There is an area that seemed like a temple to me but it has stairs up to two doors that must be opened with glowstones. There is also a water passsage in the middle of the room at the top of the main stairs. Open the two doors at the top at the same time. and turn both switches in those rooms. If you only open one door the switch inside wont stay closed. once both switches are closed a secret door above the water passage out in the main area will open. Get the tablet out of here and grab the glowstones and head back to the rotating room. Put one in the lock there and head out and on to the tomb of Cet

Vorrin

Thanks to reply. Your method needs 4 glowstones ,I think. But I have 3 glowstones,so I used create Portal spell and teleport spell, and got stone from first gem lock. I used 2 stones,as you said,so I got third tablets, thanks!! If I will search allover, can I find 4 glowstones or do I need teleport spells?

No, you only need 3

Use #1 in the slot by door 1 to open door 2 in the revolving room. Use #2 in the slot by door 2 to open door 3. Take back #1 and use with #3 to open the alcove (as explained above)

Ta da.......