The Shepherd

Tyber's first assignment after graduating from The King's Royal Academy of Dragon Riders isn't as simple as he had expected. Instead of patrolling the capital city with his dragon Rius, Tyber is hand-picked to complete an assignment for the new King.
The King's brother has been murdered. Although his assassins have been captured, the man who hired them, one known only as The Shepherd, remains at large. Tyber is tasked with tracking him down. His past acts of heroism, his awkwardness as a new hordesman, and the youth of his dragon all make him a good choice to go undercover, infiltrate the dragonjacks, and bring The Shepherd back to face justice.
But Tyber's first assignment might be his last. In a far corner of the kingdom where the King's reach is not so strong, Tyber and his companions discover an illness among the dragons that threatens to unravel the very source of the King's power.
To save the dragons and complete his mission, Tyber must put his trust, his life, and his true identity into the hands of his enemies. He will need their help to capture The Shepherd and uncover a plot to dethrone the King who has helped lift Tyber's family from poverty, and is now poised to do the same for all in the Kingdom of Cadwaller.