In 2085, when Sean's foster mother asks him to join her on Mars, he has no qualms about leaving his birth planet, for his trusted intuition suggests that Earth is in danger of self-destructing. However, Mars holds perils of its own, and as one of only 20 teenagers brought to the colony through the Asimov Project, Sean must prove himself capable of contributing to this community if he wishes to remain a part of it. The book stars a multicultural cast of teens coping with their personal insecurities. Natural dialogue and easy-flowing narrative will keep readers' attention. However, too much time is devoted to introducing the characters and detailing the rigors of Martian life. The primary conflict occurs late in the book, resulting in a somewhat rushed ending. Still, readers who devour serial fiction will forgive this flaw. In Missing, which is faster paced and more action-packed, the teens must help manage the resources necessary for their survival. When it becomes clear that obtaining new water sources is the highest priority, they assist with pipeline projects. When a work group is stranded on the surface, the colonist leader decides that rescue is too risky, and Sean and his friends take matters into their own hands. Science fiction fans will be pleased by the abundance of technical information and the scientific challenges that life on Mars presents. Others may enjoy following the growing relationships between Sean and his friends.-Jenna Miller, Alachua County Library District, Gainesville, FL Copyright 2004 Reed Business Information.