I'm stuck in part 4, I found the secret entrance in the dwarven meeting chamber as the book told me to...now I'm at this round chambre with a glowing blue crystal in the middle..but as soon as I walk around my whole party gets disintegrated by lightning traps..I can disable the trap with one person, but the next one walking over it triggers it again..and besides..what is the point of this room? do I need to get all me chars in the middle? or is there another way out of the complex?

The blue crystal has three different rings of blocks around it (from the outside ring to the inside ring).

-Just use one person for this. Do not risk your whole party, just disable the traps with one person(preferrably the one with the most hp).

You have to step on a certain block in the first ring, then another on the next, and the same on the next. The first ring, you must step on a block that has a hammer on it, it is the only picture with a hammer. After that, just save, and pick a different block and see which one disarms the trap, until you get to the middle.

After you have done this, then go outside to the room with the round table, go to the statue to the right of the door to the hidden room, and click on his arm. That will open a spiral staircase in the hidden room.

You can use the cleric spell or scroll protection from lightning to avoid some pain. You can rest in the war room and memorize the spell before your nap.

The big round table tells you which blocks to step on, just look at the symbols on the surface.