Twenty-five years ago, the alien Givers came to Earth and built four ladders 36,000 miles tall. The ladders reach into space and supply power to the whole world…until the Givers mysteriously disappear, leaving the malfunctioning ladders in their wake. Because of the way they are constructed, the only people who can fix them are a team of highly trained children. Best friends Robbi and Azure are two 11-year-olds competing for a highly coveted position at Ladder Academy, the elite institution where young ladder mechanics are trained. Soon the two friends become mixed up in a mystery that will either reveal the reason for the Givers' disappearance, or destroy the planet!