Auzou Book les cités suspendues

Meije lives in the Cité Rocheuse, where she climbs the steep cliffs every day. On one of her outings, she discovers that her father didn't die in a simple accident: it all has to do with a strange black crystal that is the object of everyone's envy... Forced to flee her Cité in the company of Andy, another climber, Meije wants to find out what this stone hides. But when their path crosses that of two foreigners on the run, they realize that the crystal is at the heart of a state plot. In the wrong hands, it could even destroy the Hanging Cities... They have no choice but to protect the ebony pyrite at all costs. A perilous quest that will take them to the end of the Bubble-World, and beyond!