Diablo 3 Walkthrough Part 24: Festering Woods

After completing the "Last Stand of the Ancients" event, keep going North and Northeast in the Festering Woods. Soon you encounter a group of Returned, Returned Archers, Plague Carriers, and a huge Plague Nest. Defeat them, then continue northwards along the path. Fight some Ghouls and Enraged Phantoms. You should soon come across the entrance to Warrior's Rest. Go inside. There are chests and lootable ancient skeletons here. Explore the dungeon, which is not so big. You might run across elite bosses here, such as the Hatemonger Wormboiler (Nightmarish).  There are also more undead to fight here.

You should reach the edge of this dungeon pretty fast, and find there the Beacon of Honor. This completes the first of your current objectives in The Broken Blade.

Keep exploring Festering Woods, searching for the Crypt of the Ancients. Watch for yellow (elite) monsters such as Grule the Brute (Waller) as they can often drop good items when killed.

There is also an event to be found here. Locate a Nephalem Monument, just southwest of the Festering Woods Waypoint, and interact with it. Some apparitions show up, and you get the new event:

Eternal War
Defeat the enemies of the spirit

There will be hordes of ghouls, enraged phantoms, and other undead attacking you. Just slaughter them all to complete this event. 

When you approach the Crypt of the Ancients, there are more Plague Carriers, and a Plague Nest guarding the crypt. Kill those, then enter the crypt. The Crypt of the Ancients is bigger then Warrior's Rest and has more monsters, but it is still not that big compared to other dungeons you've encountered, such as the Cathedral. The yellow arrow should point you to the location of the Beacon of Light.

Once you have retrieved both beacons (in this strategy guide we got the Beacon of Honor first and the Beacon of Light second, but you can get them in any order), the quest updates:

The Broken Blade
Beacon placed on Pedestals (0/2)

Your task is therefore to place their beacons on their appropriate pedestals. Exit the tomb (if still inside) and follow the yellow arrow out of the Festering Woods and past the bridge, back to where Alaric was. There are two pedestals there, one on each edge of the platform.  Place a beacon on each of those pedestals to advance the quest.

Alaric tells you that the temple is open, and instructs you to enter and defeat the guardians. Although they are his brothers, they will seek your death when you enter, he warns you.

The waypoint is nearby, so if you need to restock on potions or unload your inventory, you should use the waypoint or your town portal to quickly take care of those things. When you are ready, enter the Drowned Temple.