The object of the puzzle is to reverse the positions of the black stones and the white stones. The red stone should be at the center. Click on a stone, then click on adjacent empty space to move that stone to that space. The way that works for me is to move white stones to one end to have space to work in and then move the black stones to the opposite nearly empty side. When correctly done, a grating sound is heard.

Go left from start (sign on archway). Go to room at top of screen. Take the helmet from left at ground. Press the brick. You will hear a sound.
Go at top of screen and see an ornate door that has an opening where the lock should be.
Go 2 screens down and left. Look in opening and take the talisman.
Go back to ornate door and place the talisman on the opening where the lock should be.
See a stand and 2 alcoves behind it. Place the black sphere from inventory on the stand. Hear sounds and the button under the lamp lit up. Look in left alcove and get map of the maze-catacomb