Closer to the Heart: Book 2 by Mercedes Lackey
Saved from a harsh life of destitution as an enslaved orphan, Mags has been recruited by the King's Own Herald as a spy. In this special appointment, Mags has thrived - he is well fed, educated and treasured for his unusually powerful Gift, an ability to Mindspeak and Mindhear anyone, regardless of whether they are Gifted. This makes him the ideal undercover agent for the king.After a year of careful investigation of the gem mines, it becomes clear that half of what was being produced has been disappearing. No one knows where the gems are going, or why. Mags must go undercover to find out. As he delves deeper into the mystery, he will confront old foes, and unearth a secret that goes to the heart of the nation of Valdemar.