Elder Ironwood

Before getting Rank 3 Loremaster:

Chieftan of the Elk Clan
Initiate Wild? What are you doing here? I already gave you your orders. Perhaps you need to hear them again.

(You must be a Rank 3 Loremaster before you can continue this story. Complete quests with Maya to increase your Loremaster Reputation.)

After getting Rank 3 Loremaster:

Chieftan of the Elk Clan
Ah, Brother Wild. Still no word from the other clans? No matter. I have found a weakness that we can exploit.

Weakness?
You see, the voidspawn communicate via incredibly high or low frequency vibrations. So sensitive are they to each other's vibrations that a single void elemental can signal another from across all of lore. We're going to find a way to broadcast a signal of our own.

After completing the 'Quite the Problem' quest:

Chieftan of the Elk Clan
Well done, Initiate! you've assembled quite a distress signal. But I'm afraid that, after the many weeks of hiding, we've been discovered. We must hold off this attack until the Array can be activated!

Location: Druids

Thanks to ingomarelementary and rickyb20.