So you turn in this quest, and you get this amulet that allows you into Onyxia's lair. Afterwards, she asks you to talk to do another thing... and conveniently enough, she gets you there... by basically making you fly through the air, across Kalimdor and into the Eastern Kingdoms, where you eventually fall into the lake by Scholomance. You can just make out the small specks of Aair and Kriss... standing where I was a second before this screenshot was taken.