This quest is not available in game.
Bring Foreman Thistlenettle's Explorers' League Badge to Wilder Thistlenettle in Stormwind.
We were deep in a vast mine in Westfall, hidden beneath a barn in Moonbrook. No clue where these stinkin' thieving types came from. Anyway, the mine tunnel collapsed on us. I got out but the others... well... the others haven't been heard from.
You look like you might have better luck in there. If you could look for my brother, I'd be thankful. He always carried his Explorers' League Badge. If you can't find him, that badge would at least give me some peace of mind.