Tides Of Time
As Blake already knew, Braga was the name of the planet which he was on and from the books he read in the library, he learnt that according to historians, there had once been a large continent on it called Narash, this continent surrounded by an encompassing sea called Junos.
Though the books didn't go into specification about Narash, it made clear the fact that at some time in the past, this super large continent had split into 4 continents, 3 of which were currently known and possible to access while the other had seemingly vanished, most theorizing that it had drifted away to the other side of the world.
Within the books, Blake had seen some diagrams of Narash and then that of the content after it had split, noticing that a large chunk of it was missing from the bigger picture.