Fragment of Memory is an Elyos quest that has you speak to one Lugbug, in the Abyss, in order to recover more of your fragmented memory.
The only problem with the quest is that ol' Luggy is on an unmarked island. You can do a /where lugbug to find his direction, but not how high or low in the abyss he is.
As it happens a video was made showing exactly how to get to him. There are spoilers at the end, so you might want to just watch the first half.
