The Galaxy Travelers: The Cielo Space Chronicles

In the second installment, the Alliance invites Lauren and Julia to visit them far across the galaxy at their settlement, where five alien species have banded together to fight the horrific space monsters. The girls' family travels with them to the wondrous floating space cities where the Alliance citizens idolize the girls and honor them with a ceremony that is broadcast across the settlement.Unaware they are being stalked, the family tours the cities, where they see tropical gardens, a web palace, and arctic pools. They have a wonderful time, until their trip home goes terribly wrong. Lauren and Julia saved humanity once, and now they have to save themselves and their younger brother, Evan.