Memories of Adventures Past

There is currently a problem: If you pick up this quest below level 70, then hit level 70 during a Radiant Echoes event and return to the Portrait Room, Khadgar will no longer be there to turn in the quest.

At level 70, the quest "The War Within" should have automatically kicked in. It leads to Silithus and after a short quest chain, about two minutes not counting cut scenes, it will lead back to the Portrait Room. Khadgar will now be back and the quest can be turned in. Be aware that there is no reward for this quest though.

The "portrait room" is just down some steps from the Chamber of the Guardian where Magni is sleeping. (Beta - You want the three blue portals and not the big purple one. )

You don't need this quest to level up in the new expansion zones - this PRE-PATCH event helps you collect [currency=3089] to get better gear in preparation for the new zones. As of Beta: If you're wondering how to proceed with the new expansion zones and their quests after completing the initial quests but can't seem to find a quest giver, talk to the Tauren in Orgrimmar near the Broken Tusk inn (between Grommash Hold and the main gates), [npc=216841]. He will give you the option to send you on your merry way to the Isle of Dorn (unless you don't meet the level requirements). In Stormwind, he is standing in the main square, near Pestle's Apothecary. (What is a Tauren doing in the middle of Stormwind without a fight?)

Back to Radiant Echoes stuff:
The locations of objectives for the event, Lingering Memories, are indicated by a globe-like icons on the map (Dragonblight, Dustwallow Marsh or Searing Gorge, accessible from the portals in Legion version of Dalaran). Doing this requires some luck - being in the right place at the right time - since there are hundreds of players competing for a few mobs spawning occasionally that go down with only 2 or 3 hits. Work the objectives at the Lingering Memories locations (kill mobs, free prisoners, carry logs, etc.) until the "Memories Remaining" counter at top of your screen is near zero. When it gets to zero, the boss will spawn. The bosses drop 480+ gear and also "regional" memories like [item=223644], which you collect to purchase [item=219325]. Visit How to Obtain a Heirloom Ring for more information on this.

There are daily weekly quests in each of the 3 zones that are part of the Radiant Echoes event: Only Darkness in Dragonblight, Broken Masquerade in Dustwallow Marsh right outside [zone=2159] and Champion of the Waterlords in Searing Gorge). The quest givers are near the Dalaran portals in each of the 3 zones.

(Note, though once individual, these quests are now account-wide (complete only once per account, per week), similar to When Time Needs Mending.)

In the current beta the Lich King memory for Only Darkness does not spawn in the area marked on the map, but spawns instead on the main path a little ways South of the Wyrmrest Temple. Check your map and you will see his icon on when he spawns.