The Broken World Book Two - StarSword. Broken World, #2

Although at war with the land itself, men have survived by paving their streets and surrounding their cities with dried Earthblood. In doing so, they have enraged the souls further, and only the chosen are safe under Chanter's protection. The Black Riders have also arrived ahead of them, and continue their deadly march across the land, slaying all Truemen in their path. Chanter takes Talsy and Kieran to search for more chosen, who are trapped in the safety of the cities.
The people strive to elude their fate, and a mad prince has inherited a pebble that holds the power to break the world. He sends men to capture Talsy in a bid to save himself, thinking that taking her hostage will force Chanter to protect him. To save her, Chanter does the unthinkable; he creates a forbidden Mujar weapon and gives it to the only warrior amongst the chosen - Kieran. The Starsword holds the Powers of Earth and Fire and, if it falls into the wrong hands, impossible though that should be, it could be used to break the Staff of Law.