Laddertop 2

Laddertop 2: The Laddertop Series, Book 2 by Emily Janice Card and Orson Scott Card

The second Laddertop book ramps up the drama. There are "rebels" that are concerned about the unknowns of laddertop. They recruit a few kids and other scientists for their space mission. There is also some more information found about the special symbol. A space object is approaching the earth. Is it benevolent? Or is it bent on destruction? The book ends on a cliffhanger... That was not resolved for a decade. While these were first released as graphic novels, they have recently been moved to audiobooks, with the final book only as audiobook. There was a big cast for this, so some needed to be left off to get under the label limit.