The Ember Blade: The Darkwater Legacy, Book 1 / Chris Wooding, Simon Bubb, Gollancz,

A land under occupation. A legendary sword. A young man's journey to find his destiny.  

Aren has lived by the rules all his life. He's never questioned it; that's just the way things are. But then his father is executed for treason, and he and his best friend, Cade, are thrown into a prison mine, doomed to work until they drop. Unless they can somehow break free.... 

But what lies beyond the prison walls is more terrifying still. Rescued by a man who hates him yet is oath-bound to protect him, pursued by inhuman forces, Aren slowly accepts that everything he knew about his world was a lie. The rules are not there to protect him or his people but to enslave them. A revolution is brewing, and Aren is being drawn into it, whether he likes it or not.  

The key to the revolution is the Ember Blade. The sword of kings, the Excalibur of his people. Only with the Ember Blade in hand can their people be inspired to rise up...but it's locked in an impenetrable vault in the most heavily guarded fortress in the land.  

All they have to do now is steal it....

Read by Simon Bubb.