The Writers' Circle

...
Gavin shone his light on the huge wall in the cave. The black dolomite wall seemed to swallow the light from his headlamp. His inspection stopped on a peculiar marking shoulder height and to his right. He moved closer and saw a small golden circle reflecting his light. In the black rock, it appeared to have a light of its own. Gave touched he gold, it was cold. He moved his finger over the edge and a thick dust layer hugged his finger revealing more of the golden disk.  With the palm of his hand, he cleaned of all the dust to reveal a one-meter diameter disk with a line connected to triangles engraved on it. His mind was racing. Did they discover some valuable treasures or what? The fact that they were stuck in this cave skipped his mind in his excitement. He ran his finger along the engraved line, tracing it to the first triangle. When his finger touched the first triangle, he could swear he heard a faint click. Maybe it was some kind of lock. He carried on tracing the line to the next triangle. There it was again, more distinct this time, a click. The line split and the rest of the triangles connected in a network. Gavin felt that he should follow the line and trace the triangle from the left. 

Stefan reached the top of the calcite pillar his breathing labored.  The top of the pillar formed a plateau from which rose a crystalline altar. Catching his breath, he inspected the object. There was nothing funny about it, accept for a perfect circle running down the exact center of the altar. He assumed the block was of quartz. His headlamp penetrated the block and it reflected out the sides in fantastic displays of color. He leant over the pillar and inspected the hole. His light could not penetrate the darkness to reveal the end of the hole. Suddenly he saw a red flicker in the crystalline pipe. He jerked back thinking it might shoot out the hole. Was he imagining things? He leaned over again. There it was, brighter this time, there was no mistaking it, and it was bigger as well.

Gavin finished tracing all the triangles; there was no door opening, no cave wall moving away to reveal untold reaches. He was a bit disappointed, but he did not really believe that they would discover something. He stood back from the plate, shining his light on it. Except for the lines and the triangles, it had no other markings. He wondered who could have placed it there and for what reason. Stefan calling him in an urgent voice broke his reverie. 
'What's up buddy' he shouted back.
'You have to come check this out!' more insistent now.
'Alright, I'm coming.'
He ran to the pillar and started climbing up the spiral shelf.
'Hurry,' he heard Stefan shouting through his heavy breathing.  
As he reached the top of the pillar and bent over trying to catch his breath the crystalline box started glowing in a red hue. Stefan pointed to it but said nothing. Gavin forgot his breathing exercises and stood up. The Block turned from a red hue to a bright red glow. The crystal targeted the light in beams forcing it out into the cave. The pillar started to vibrate and they could hear a deep hum emanating from deep inside it. 
'What is...?' ' Stefan tried to say but his voice was drowned by a loud hiss. From the hole exploded a sheath of red light with a brilliant white light inside it. Both of them fell to the ground. The hissing stopped and the cave fell silent. The beam of light faded into a Smokey substance and inside the white smoke stood a naked old man, a brilliant white aura shining around him.
...