The Edge Chronicles: The Cade saga, book 1 : The nameless one
Paul Stewart et Chris Riddell2016

Cade Quarter has never met his uncle, the infamous ‘descender’ Nate Quarter, who years ago committed heresy by lowering himself over the cliff-face of the Edge. But Nate has returned, and the Academy of Flight is looking for revenge against all of his supporters – including Cade. So now Cade has to run.