An original science fiction manga by the bestselling author of Ender's Game and his daughter


Twenty-five years ago, the alien Givers came to Earth. They gave the human race the greatest technology ever seen-- four giant towers known as Ladders that rise 36,000 miles into space and culminate in space stations that power the entire planet. Then, for reasons unknown, the Givers disappeared. Due to the unique alien construction of the Laddertop space stations, only a skilled crew of children can perform the maintenance necessary to keep the stations up...