Pendragon series

Bobby finds himself in the territory of Cloral, a world entirely covered by water, which is nearing a huge disaster. He learns that it is up to him to help rid the area of marauders and locate the legendary lost land of Faar, which may hold the key to Cloral's survival.

Taking advantage of a severe drought and the long-standing distrust between two tribes, the demonic Saint Dane attempts to take over Loor's home planet of Zadaa, opposed once again by the teenaged Pendragon and other Travelers.

With Saint Dane seemingly on the verge of toppling all of the territories, Pendragon and Courtney set out to rescue Mark and find themselves traveling--and battling--their way through different worlds as they try to save all of Halla. When Bobby Pendragon first arrives on the tropical world of Ibara, he finds paradise. As he works to uncover clues about the turning point this seemingly idyllic territory will soon face, all he can determine is that...

Each of the Travelers returns home to learn the truth about their origins before being reunited for a final, ineveitable confrontation with Saint Dane, whose efforts to control Halla are destroying its very foundations.