The Hailona Prophecy by J. Lance Sanders
Approx. 60,760 words.
Published on April 30, 2011.
Four kids from Hawaii travel through an energy portal to a tropical island—in another dimension—called Sandtopia. There, they are hunted down by an evil and depraved queen who is made entirely out of sand: the Sand Queen. The kids must test their mettle and try their best to thwart and topple her.