A Flash of Bronze...
Speak with Chromie outside of the Seat of Knowledge in the Vale of Eternal Blossoms.
Description
As you survey the devastation of the vale, a flash of bronze catches your eye. Unless you're mistaken, a tiny gnome is trying to catch your attention from the balcony above Mogu'shan Palace, just outside of the Seat of Knowledge.
You should see what she wants.
Rewards
You will also receive:
If the character has already visited Timeless Isle, Chromie will say the following instead of giving the follow-up quest:
This quest is received automatically after logging in during Patch 5.4.0 as an Alliance character.
This quest chain is the main quest line for the Timeless Isle.