Fight folks from entrance of the Faery Realm to the Road to Daru using Bug-a-boo.
This quest is unlocked in Chapter 3 of the storyline. It is available to Keats during the night by speaking with Ganconer.
Head north, follow the path, go north, continue north and go around the tree to the exit. Defeat the folks and break the memory stone for some health. Take the northern exit, go north, then east, then east again and lastly go north.