The Baker's Boy — J.V. Jones

At vast Castle Harvell, where King Lesketh lies dying, two fates collide. In her regal suite, young Melliandra, the daughter of an influential lord, rebels against her forced betrothal to the sinister Prince Kylock. In the kitchens, an apprentice named Jack is terrified by his sudden, uncontrolled power to work miracles. Together they flee the castle, stalked by a sorcerer who has connived for decades to control the crown, even committing supernatural murder to advance his schemes.

And a young knight begins a quest, leaving behind his home and family to seek out the treacherous Isle of Larn, where lies a clue to his desperate search for the truth.