The Great Conjunction is the end of the world...or the beginning.  

-Aughra

The Great Conjunction is an event that occurs once every thousand years. The conjunction happens when the three suns of Thra line up in the sky forming an intense beam of light. Due to its placement on the planet, this beam will shine directly onto the Crystal. The burning light focused towards Thra during the very first is responsible for creating the Great Shaft and revealing the Crystal.

During one Great Conjunction the crystal cracked and the UrSkek divided. The Gelflings made a prophecy stating that one of them would heal the crystal and restore order during the next Conjunction. Aughra lost her eye during one of the Great Conjunctions.