Laddertop

Eleven-year-old best friends Robbi and Azure are excited when they are accepted into Laddertop Academy to be trained to work on the Ladders, technology given to the human race by aliens that supply power to the entire planet and the space stations they support. Although only one of them makes it to the Ladders, the girls eventually end up working together to solve an ancient mystery that could mean either the end or the salvation of the human race.