After you arrive at Al'Taieu you will receive the title "Seeker of the Light" and key item Light of Al'Taieu, and your mission log changes to Chapter 8. Make your way to the spires you can see on the horizon.
Head to a large bridge leading up to the Celestial Nexus and check the Crystalline Field door (H-11) for a cutscene.
After the cutscene you need to visit three Rubious Crystals. The first crystal is located at a small tower south of the bridge with the Crystalline Field. Checking each crystal will spawn three Ru'aern NMs, each with their own job and appropriate 2-hours.
Check the Rubious Crystal after they are dead for a cutscene.
It'd be a good idea to aggro and kill the Om'phuabo (sharks) surrounding this tower. Better to kill before than to have them aggro once you've spawned the NMs.
Completing the Mission
Once you visit all three towers and get the three cutscenes there, head back to the Crystalline Field (H-11) and zone into the Grand Palace of Hu'Xzoi.
Head forward and check the Gate of the Gods (H-8) for a final cutscene and your reward.
SE has put Home Point # 1 just to the right as you approach the Gate of the Gods. Very handy for coming back later. :)
NOTE: YOUR MISSION LOG WILL NOT UPDATE YET. It only updates after checking the East Particle Gate for another cutscene.
The celestial capital of Al'Taieu truly exists. Though vastly altered during the ten thousand-year span of their seclusion, the ancients remain alive in the city. Nag'molada heads for the palace, while you and your companions follow in his wake...
SPOILER WARNING: Click here for additional details about this story line.