First, let me tell you more of the task you must complete. The druids in Darnassus use the water of the moonwells of Teldrassil, and their moonwell must be replenished from time to time. Using these specially crafted phials, you can collect the water of the moonwells.
Take this vessel to the moonwell outside of Starbreeze Village to the east, and fill it with some of its waters, then return to me. When you have completed your task, I shall continue the story where Tenaron left off...
After the Battle of Mount Hyjal, we were without direction. Nordrassil smoked from the fire it unleashed, and our immortality--the very essence of our beings!--was lost.
It was in this trying time that the Betrayer was freed from his prison, and Shan'do Stormrage disappeared. A dark time for all.