In Baren's Peril, you must travel to a cave in southern Silverpine Forest and kill undead creatures there.
This place is a bit hard to find. The screenshot on thottbot is somewhat useful: . The cave is located in the hills south of Ambermill, but you need to get to it from the south side of the hills. The coordinates are 60,74.
I have received reports that a group of undead are holing up to prepare for an attack against us. Armed with this information, we can turn the tables and attack them first, nipping their little plan in the bud.
Unfortunately, my information is spotty, at best. They are reported to be hiding in a location known as Beren's Peril. The exact location is unknown, but it appears to be a cave in the hills, near a pocket of Dalaran wizards.
I trust your resourcefulness. Find them, and put them down.
You will be rewarded with the following:
Have you located their base yet, <name>? Time is of the essence!
If our scouts and agents continue to procure valuable information such as this, we shall have the Lich King's Scourge removed from our lands in no time.