User blog comment:Woest/Raven Tail/@comment-4829046-20131119155845/@comment-24066070-20131119184048

Haha the spotlight joke is nice one :D

Yeah I get your point that it has to be something impressive with all these lights and not just an old, dusty scroll. Then again Mavis may have imbued it with some of her magic (like her grave, which contained Fairy Glitter) and Gildarts may have felt a powerful wave of magic coming from LH.

The only things known about LH are that it is something that was written by Mavis, that Makarov considers it the guild's dark secret and that Mavis considers it the guild's light. The only thing that I can think of which could be written and depending on the point of view, seen as darkness or light, is information. Whether this information concerns Zeref, Dragons, advanced magic, a prophecy or something else remains to be seen.

For all I know, it might even be some sort of Book of Mavis (terrible name, but couldn't come up with another one)