Out of This World — Douglas E. Richards

Zachary and Jenna Lane are a brother and sister pair who would much rather tease and trick each other than work together. But when their parents vanish before their eyes through a mysterious shimmering portal, the two kids join forces and adventure through a series of fantastic worlds in an effort to rescue them. But each world is more treacherous than the last, and staying alive for even a day will prove to be the ultimate test of their wits, courage, and determination. And when they finally puzzle out what is happening to them and why, the impossible happens: things get even worse. Because far more is at stake than just their lives. And the odds against them could not be any greater . . . Out of This World is a fast-paced adventure sure to delight young and old alike, packed with breakneck action, brilliant escapes, thrilling cliffhangers, and plenty of heart. Note: Richards is also the author of the YA science fiction series, The Prometheus Project, the adult thriller, WIRED, which was the bestselling Kindle book of 2011 in two major categories: science fiction and technothrillers, its sequel AMPED, and THE CURE.